Both asm.js and syntax parsing can abort and rewind parsing of an inner function.
The bookkeeping to make sure that a class's constructor FunctionBox is only set once is not worth it -- duplicate constructor definitions already throw an early error.
Bug 1342553 - Part 0.1: Use try-catch for IteratorClose in for-of
Bug 1343072 - Update HasLiveStackValueAtDepth to follow the change in
JSTRY_FOR_OF
Bug 1344753 - Update for-of stack depth in
ControlFlowGenerator::processWhileOrForInLoop
Issue #74
CallTypedArrayMethodIfWrapped (and the CallNonGeneric machinery throughout the
engine) unwraps the `this` argument, but the other arguments are only rewrapped
for the target compartment.
The pattern being used before this patch to get the length of a TypedArray or
possible TypedArray wrapper is:
`callFunction(CallTypedArrayMethodIfWrapped, O, O, "TypedArrayLength")`
The first `O` is the `this` value and the second is an argument. If `O` is a
cross-compartment wrapper, this works fine. The first `O` is unwrapped, revealing
the actual TypedArray object; the second `O` is rewrapped for that TypedArray's
compartment, producing the same TypedArray.
However, if `O` is a same-compartment wrapper, this doesn't work. The first `O` is
unwrapped, revealing the actual TypedArray object in the same compartment;
rewrapping the other `O` does nothing to it, since it is already an object in the
target compartment. Thus TypedArrayLength receives a `this` value that's an
unwrapped TypedArray, but an argument that is still a wrapper.
The fix is to have CallTypedArrayMethodIfWrapped targets only expect `this`
to be an unwrapped TypedArray.
