Also support patterns in ``for (var p in/of ...)``
This CL extends the rewriting we used to do for ``for (let p in/of...)`` to
``for (var p in/of ...)``. For all for..in/of loop declaring variable,
we rewrite
for (var/let/const pattern in/of e) b
into
for (x' in/of e) { var/let/const pattern = e; b }
This adds a small complication for debugger: for a statement
for (var v in/of e) ...
we used to have
var v;
for (v in/of e) ...
and there was a separate breakpoint on ``var v`` line.
This breakpoint is actually useless since it is immediately followed by
a breakpoint on evaluation of ``e``, so this CL removes that breakpoint
location.
Similiraly, for let, it used to be that
for (let v in/of e) ...
became
for (x' in/of e) { let v; v = x'; ... }
``let v``generetaed a useless breakpoint (with the location at the
loop's head. This CL removes that breakpoint as well.
R=arv@chromium.org,rossberg@chromium.org
BUG=v8:811
LOG=N
Review URL: https://codereview.chromium.org/1149043005
Cr-Commit-Position: refs/heads/master@{#28565}
This patch:
- Refactors Parser::ParseVariableDeclarations
- Introduces Parser::PatternMatcher class
- Implements matching a single variable pattern
- Implements rudimentary matching against object literal pattern
as a proof of concept
R=arv@chromium.org,rossberg@chromium.org
BUG=v8:811
LOG=N
Review URL: https://codereview.chromium.org/1130623004
Cr-Commit-Position: refs/heads/master@{#28345}
