This is in preparation to implementing exception prediction for async
functions. Each handler table entry can now predict "caught", "uncaught", or
"promise". The latter indicates that the exception will lead to a promise
rejection.
To mark the relevant try-catch blocks, we add a new native syntax.
try { } %catch (e) { } indicates a TryCatchStatement with the "promise"
prediction.
The previous implementation of using the function to tell the relevant
try-catch apart from inner try-catch blocks will not work for async functions
since these can have inner try-catch blocks inside the same function.
BUG=v8:5167
Review-Url: https://codereview.chromium.org/2161263003
Cr-Commit-Position: refs/heads/master@{#37966}
This switches full-codegen to no longer push and pop StackHandler
markers onto the operand stack, but relies on a range-based handler
table instead. We only use StackHandlers in JSEntryStubs to mark the
transition from C to JS code.
Note that this makes deoptimization and OSR from within any try-block
work out of the box, makes the non-exception paths faster and should
overall be neutral on the memory footprint (pros).
On the other hand it makes the exception paths slower and actually
throwing and exception more expensive (cons).
R=yangguo@chromium.org
TEST=cctest/test-run-jsexceptions/DeoptTry
Review URL: https://codereview.chromium.org/1010883002
Cr-Commit-Position: refs/heads/master@{#27440}
