Commit Graph

620 Commits

Author SHA1 Message Date
dslomov@chromium.org
fc73052dc2 Externalization API for ArrayBuffer
R=svenpanne@chromium.org

Review URL: https://codereview.chromium.org/15001041

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14770 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-05-23 10:01:42 +00:00
verwaest@chromium.org
36e91242fd Make Object.freeze fast
This patch both speeds up the freeze operation itself, but also
allows properties to remain in fast mode. Objects with non-empty
elements backing stores still end up with slow elements.

Relanding r14758 and r14759 with fix for Test262: only mark properties
and elements READ_ONLY if they are not JS setter/getters. Tightened up
tests to assert frozen-ness, and added targeted tests for the new code
(covering accessors).

BUG=v8:1858, 115960
R=verwaest@chromium.org

Review URL: https://chromiumcodereview.appspot.com/15691007

Patch from Adam Klein <adamk@chromium.org>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14762 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-05-23 07:05:58 +00:00
adamk@chromium.org
4d48bb832f Revert "Make Object.freeze fast"
and "Fix Object.freeze on dictionary-backed arrays to properly freeze elements"

This reverts r14758 and r14759 due to introducing failures in Test262

TBR=verwaest@chromium.org

Review URL: https://codereview.chromium.org/15681004

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14760 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-05-22 21:27:00 +00:00
adamk@chromium.org
648e99e308 Make Object.freeze fast
This patch both speeds up the freeze operation itself, but also
allows properties to remain in fast mode. Objects with non-empty
elements backing stores still end up with slow elements.

BUG=v8:1858, 115960
R=verwaest@chromium.org

Review URL: https://codereview.chromium.org/14888005

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14758 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-05-22 18:53:58 +00:00
yangguo@chromium.org
9960b24694 Fix unexpected elements transition in JSON.parse
R=verwaest@chromium.org
BUG=241344

Review URL: https://chromiumcodereview.appspot.com/15739003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14746 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-05-22 13:24:18 +00:00
dcarney@chromium.org
1045d62733 implement fast ReturnValue setters
R=svenpanne@chromium.org
BUG=

Review URL: https://codereview.chromium.org/15398008

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14738 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-05-22 06:35:38 +00:00
verwaest@chromium.org
9f32d94cb3 Don't create new maps in CurrentMapForDeprecated.
R=yangguo@chromium.org

Review URL: https://chromiumcodereview.appspot.com/15358005

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14728 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-05-21 11:20:24 +00:00
dslomov@chromium.org
2ff3e2e0f4 Preallocate transitioned maps for TypedArrays.
R=hpayer@chromium.org

Review URL: https://codereview.chromium.org/15172003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14693 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-05-15 15:23:53 +00:00
danno@chromium.org
cf1b80703f Improve trace_opt output to help find compilation problems
R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/14978003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14636 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-05-13 11:10:31 +00:00
mstarzinger@chromium.org
883d9c4b1c Prevent flushing of code that was set with %SetCode.
This makes sure that shared function infos that break the one-to-one
mapping to code are marked as un-flushable. Otherwise enqueuing through
the GC meta-data field in the code object doesn't work.

R=rossberg@chromium.org
TEST=cctest/test-api/Threading4

Review URL: https://codereview.chromium.org/14710015

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14635 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-05-13 10:59:00 +00:00
verwaest@chromium.org
df57747fc4 Track heap objects.
R=danno@chromium.org

Review URL: https://chromiumcodereview.appspot.com/14996004

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14625 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-05-10 17:17:50 +00:00
verwaest@chromium.org
52008429b7 Use mutable heapnumbers to store doubles in fields.
R=danno@chromium.org

Review URL: https://chromiumcodereview.appspot.com/14850006

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14597 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-05-08 15:02:08 +00:00
wingo@igalia.com
75d939aceb Generators save and restore stack handlers
This CL adds machinery to unwind stack handlers from the stack and store
them into a generator's operand array.  It also includes routines to
reinstate them.  Together this allows generators to yield within
try/catch and try/finally blocks.

BUG=v8:2355
R=mstarzinger@chromium.org
TEST=mjsunit/harmony/generators-iteration

Review URL: https://codereview.chromium.org/14031028

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14586 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-05-08 08:08:23 +00:00
verwaest@chromium.org
0b1a9c9e3d Free up 11 bits in fast-mode PropertyDetails by removing the enumeration-index.
The descriptors are nowadays ordered in order of addition, so that info was
duplicated.

Review URL: https://chromiumcodereview.appspot.com/14622005

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14571 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-05-07 13:09:23 +00:00
verwaest@chromium.org
fd9c82a618 Update deprecated maps before generating optimized code.
Review URL: https://chromiumcodereview.appspot.com/14847008

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14522 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-05-02 15:40:07 +00:00
verwaest@chromium.org
99e17bb12a Track storage types of instance variables.
Review URL: https://chromiumcodereview.appspot.com/14146005

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14464 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-04-26 15:30:41 +00:00
dcarney@chromium.org
c50304209a remove IsOneByteConvertible
R=ulan@chromium.org
BUG=

Review URL: https://codereview.chromium.org/14298021

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14461 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-04-26 14:08:18 +00:00
dcarney@chromium.org
0a32b57594 HasOnlyAsciiChars can return incorrect results. Fixup usages and rename.
R=ulan@chromium.org
BUG=

Review URL: https://codereview.chromium.org/14509012

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14453 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-04-26 11:34:44 +00:00
mvstanton@chromium.org
e751ad06d9 Constructed arrays can be created with Hydrogen code stubs. The feature is still off by default (--optimize-constructed-arrays).
BUG=

Review URL: https://codereview.chromium.org/12385014

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14441 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-04-25 16:00:32 +00:00
mstarzinger@chromium.org
71dc9e165f Capture receiver in generator object
Previously there has been no reason to context-allocate the receiver, so
access to the receiver always goes through the stack.  This was failing
with generators, which assumed that forcing context allocation would
relieve the need of storing anything but the context and the function on
the stack.

This CL adds a slot in generator objects to capture the receiver, and
restores it when resuming a generator.

BUG=v8:2355
TEST=mjsunit/harmony/generators-iteration

Review URL: https://codereview.chromium.org/14158006

Patch from Andy Wingo <wingo@igalia.com>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14434 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-04-25 10:59:09 +00:00
danno@chromium.org
f8ddf3a262 Add monomorphic CompareNilICs and Crankshaft support
R=mvstanton@chromium.org

Review URL: https://codereview.chromium.org/14367018

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14407 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-04-24 11:32:17 +00:00
mstarzinger@chromium.org
0f348e5592 Generator objects can suspend
* src/ast.h:
* src/parser.cc: Differentiate between the different kinds of yields, in
  anticipation of boxing return values.  Parse `return' into `yield' in
  a generator.

* src/runtime.h:
* src/runtime.cc (Runtime_SuspendJSGeneratorObject): New horrible
  runtime function: saves continuation, context, and operands into the
  generator object.

* src/arm/full-codegen-arm.cc (VisitYield):
* src/ia32/full-codegen-ia32.cc (VisitYield):
* src/x64/full-codegen-x64.cc (VisitYield): Arrange to call
  SuspendJSGeneratorObject.  If the call returns the hole, we suspend.
  Otherwise we resume.

BUG=v8:2355
TEST=These codepaths are tested when the generator is first invoked, and so
are covered by mjsunit/harmony/generators-objects.js.

Review URL: https://codereview.chromium.org/13704010

Patch from Andy Wingo <wingo@igalia.com>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14353 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-04-19 14:11:23 +00:00
danno@chromium.org
bc04544f02 Replace math.h with cmath
This will make it easier to use other STL headers in the future

Review URL: https://codereview.chromium.org/14362023

Patch from Jochen Eisinger <jochen@chromium.org>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14352 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-04-19 13:26:47 +00:00
danno@chromium.org
244fa50a80 Make it possible to Crankshaft all kinds of stubs.
Review URL: https://codereview.chromium.org/14307006

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14323 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-04-18 09:50:46 +00:00
dslomov@chromium.org
c1a19275d3 First cut at impementing ES6 TypedArrays in V8.
BUG=

Review URL: https://codereview.chromium.org/13975012

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14285 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-04-16 14:16:30 +00:00
mstarzinger@chromium.org
591a8ec86c Calling a generator function returns a generator object
* src/heap.h:
* src/heap.cc:
* src/objects-debug.cc:
* src/objects-inl.h:
* src/objects-printer.cc:
* src/objects-visiting.cc:
* src/objects.cc:
* src/objects.h: Define a new object type, JSGeneratorObject.

* src/factory.h:
* src/factory.cc (NewFunctionFromSharedFunctionInfo): Generator function
  inital maps construct the new JS_GENERATOR_OBJECT_TYPE objects, not
  generic JSObjects.

* src/runtime.h:
* src/runtime.cc (Runtime_CreateJSGeneratorObject):
* src/arm/full-codegen-arm.cc (Generate):
* src/ia32/full-codegen-ia32.cc (Generate):
* src/x64/full-codegen-x64.cc (Generate): Before visiting generator
  bodies, arrange to construct and return a generator object.

* test/mjsunit/harmony/generators-objects.js: Add tests for the
  properties and prototype of generator objects.

BUG=v8:2355
TEST=mjsunit/harmony/generators-objects

Review URL: https://codereview.chromium.org/13542002

Patch from Andy Wingo <wingo@igalia.com>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14264 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-04-15 12:29:44 +00:00
rossberg@chromium.org
a96ea2faa1 Put common case first
This might fix a 2% regression that we might be observing for CL 14128.

R=verwaest@chromium.org
BUG=

Review URL: https://codereview.chromium.org/13811021

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14206 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-04-10 09:53:43 +00:00
yangguo@chromium.org
996a80df45 Fix OSR for nested loops.
R=jkummerow@chromium.org
BUG=v8:2618

Review URL: https://chromiumcodereview.appspot.com/13811014

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14202 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-04-10 09:24:31 +00:00
verwaest@chromium.org
64f34cb761 Eagerly parse expected transitions in JSON.
Review URL: https://chromiumcodereview.appspot.com/13741010

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14191 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-04-09 16:49:28 +00:00
rossberg@chromium.org
b449691db2 ES6 symbols: fix corner cases of equality operators
R=mstarzinger@chromium.org
BUG=

Review URL: https://codereview.chromium.org/13552002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14128 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-04-03 17:06:22 +00:00
mstarzinger@chromium.org
2816f19680 Add parser support for generators.
This patchset begins by adding support for "yield", which is unlike other tokens
in JS. In a generator, whether strict or classic, it is a syntactic keyword.
In classic mode it is an identifier. In strict mode it is reserved.

This patch adds YIELD as a token to the scanner, and adapts the preparser and
parser appropriately. It also parses "function*", indicating that a function is
actually a generator, for both eagerly and lazily parsed functions.

Currently "yield" just compiles as "return".

BUG=v8:2355
TEST=mjsunit/harmony/generators-parsing

Review URL: https://codereview.chromium.org/12646003
Patch from Andy Wingo <wingo@igalia.com>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14116 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-04-02 17:34:59 +00:00
dslomov@chromium.org
944c577c7b First steps towards implementing ArrayBuffer &co in V8
BUG=

Review URL: https://codereview.chromium.org/13064003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14091 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-03-28 12:50:18 +00:00
verwaest@chromium.org
2541f2507f Add AssertNoAllocation to ensure TransitionArray* transitions is safe.
Review URL: https://chromiumcodereview.appspot.com/12583013

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14066 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-03-25 15:59:08 +00:00
jkummerow@chromium.org
2159b470d7 Fix crash involving zombie maps escaping from the JSON parser's underground lab
Zapping is required since transition arrays contain weak references to maps: At the end of a GC cycle, ClearNonLiveTransitions removes references to dead maps from transition arrays. If a marked transition array with weak (dead) references is replaced by another transition array before the end of the GC cycle, dead references are not removed from the replaced transition array. If the replaced transition array is kept alive by a handle, marking will crash when trying to mark the first reference to a dead map.

Review URL: https://codereview.chromium.org/12987013

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14063 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-03-25 15:18:52 +00:00
rossberg@chromium.org
2657e432e4 ES6 symbols: implement name property
Adds string-valued name property to symbols, and uses it for pretty-printing.

Requires allocating symbols in pointer space, with a custom iterator to skip the unboxed hash.

R=mstarzinger@chromium.org
BUG=

Review URL: https://codereview.chromium.org/12459026

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14053 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-03-22 16:51:28 +00:00
svenpanne@chromium.org
e4e4447305 Pass Isolates explicitly in Deoptimizer-related code.
Removed a few ancient useless ASSERTs on the way. Reduced the number of train wrecks.

BUG=v8:2487

Review URL: https://codereview.chromium.org/12917002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@13965 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-03-18 13:57:49 +00:00
verwaest@chromium.org
37a2e32496 Unify kMaxArguments with number of bits used to encode it.
Increase the number of bits by 1 by making Flags unsigned.

BUG=chromium:211741

Review URL: https://chromiumcodereview.appspot.com/12886008

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@13964 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-03-18 13:35:17 +00:00
dcarney@chromium.org
fbe34d4ba5 remove latin-1 flag
R=yangguo@chromium.org
BUG=

Review URL: https://codereview.chromium.org/12700008

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@13939 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-03-13 20:04:50 +00:00
yangguo@chromium.org
479e39a058 Parallel recompilation: remove interrupt for code generation.
R=jkummerow@chromium.org
BUG=

Review URL: https://chromiumcodereview.appspot.com/12488006

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@13917 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-03-12 18:03:18 +00:00
svenpanne@chromium.org
1a2454d752 Consistently pass a Heap* to HashTable-related AsObject methods.
This is basically a follow-up CL to https://code.google.com/p/v8/source/detail?r=13908.

BUG=v8:2487

Review URL: https://codereview.chromium.org/12546024

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@13911 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-03-12 10:05:42 +00:00
svenpanne@chromium.org
e02315ef77 Added an Isolate parameter to some HashTable/Dictionary methods. TypeFeedbackOracle tweaks.
BUG=v8:2487

Review URL: https://codereview.chromium.org/12764003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@13908 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-03-12 07:06:36 +00:00
mstarzinger@chromium.org
bbc9f5362a Fix heap snapshot creation for Harmony collections.
R=yangguo@chromium.org
BUG=v8:2535
TEST=cctest/test-api/Regress2535

Review URL: https://codereview.chromium.org/12615005

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@13897 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-03-11 11:31:53 +00:00
dcarney@chromium.org
25058ddd85 Runtime version of declarative native accessors.
R=svenpanne@chromium.org
BUG=

Review URL: https://codereview.chromium.org/12297012

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@13856 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-03-07 11:42:58 +00:00
dcarney@chromium.org
07e2494735 Added back some utf8 optimizations
R=yangguo@chromium.org
BUG=https://code.google.com/p/v8/issues/detail?id=2551

Review URL: https://codereview.chromium.org/12390057

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@13842 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-03-06 15:39:57 +00:00
verwaest@chromium.org
34697f5b12 Make IC patching resilient to flushing of the original target() ic.
Review URL: https://chromiumcodereview.appspot.com/12451003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@13831 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-03-05 17:38:35 +00:00
rossberg@chromium.org
5c93b18eb2 ES6 symbols: Allow symbols as property names
Since symbols and strings share a common representation, most of this change is about consistently replacing 'String' with 'Name' in all places where property names are expected. In particular, no new logic at all is necessary for maps, property dictionaries, or transitions. :) The only places where an actual case distinction is needed have to do with generated type checks, and with conversions of names to strings (especially in logger and profiler).

Left in some TODOs wrt to the API: interceptors and native getters don't accept symbols as property names yet, because that would require extending the external v8.h.

(Baseline CL: https://codereview.chromium.org/12296026/)

R=verwaest@chromium.org,mstarzinger@chromium.org
BUG=v8:2158

Review URL: https://codereview.chromium.org/12330012

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@13811 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-03-04 15:00:57 +00:00
verwaest@chromium.org
590a3f8811 Polymorphism support for load IC.
Review URL: https://chromiumcodereview.appspot.com/12340112

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@13801 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-03-04 14:03:27 +00:00
mvstanton@chromium.org
c4caf766bf Allocation Info Tracking, continued.
Addresses missing cases for array literals.
Adds support for "new Array()" call sites. This isn't complete yet, I have to run with --noinline_new.

BUG=

Review URL: https://codereview.chromium.org/11818021

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@13790 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-03-01 16:06:34 +00:00
rossberg@chromium.org
090d09d685 ES6 symbols: Implement Symbol intrinsic and basic functionality
- Add --harmony-symbols flag.
- Add Symbol constructor; allow symbols as (unreplaced) return value from constructors.
- Introduce %CreateSymbol and %_IsSymbol natives and respective instructions.
- Extend 'typeof' code generation to handle symbols.
- Extend CompareIC with a UNIQUE_NAMES state that (uniformly) handles internalized strings and symbols.
- Property lookup delegates to SymbolDelegate object for symbols, which only carries the toString method.
- Extend Object.prototype.toString to recognise symbols.

Per the current draft spec, symbols are actually pseudo objects that are frozen with a null prototype and only one property (toString). For simplicity, we do not treat them as proper objects for now, although typeof will return "object". Only property access works as if they were (frozen) objects (via the internal delegate object).

(Baseline CL: https://codereview.chromium.org/12223071/)

R=mstarzinger@chromium.org
BUG=v8:2158

Review URL: https://codereview.chromium.org/12296026

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@13786 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-03-01 13:28:55 +00:00
rossberg@chromium.org
764e1a0fcf ES6 symbols: Introduce Symbol class, along with abstract Name class
The new instance type 'Symbol' represents ES6 symbols (a.k.a. private/unique names). Currently, symbols are simple data objects that only carry a hash code, random-generated upon allocation.

The new type 'Name' now serves as the common super class for strings and symbols, and is supposed to represent property names. We will eventually migrate APIs from String to Name for the standard key type.

Strings and symbols share the same hash field representation, via the Name class. This way, we should be able to use the same code paths for symbols and internalized strings in most cases. Also, Symbol's instance type code is allocated adjacent to internalized string codes in the enum, allowing a simple range check for the common case.

Baseline CL: https://codereview.chromium.org/12210083/

R=mstarzinger@chromium.org
BUG=

Review URL: https://codereview.chromium.org/12223071

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@13783 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2013-03-01 10:34:31 +00:00