Also, make %GeneratorGetSourcePosition fail if called on a suspended Ignition generator
(rather than return nonsense). This functionality is currently not implemented.
BUG=v8:4907
Review-Url: https://codereview.chromium.org/2049663002
Cr-Commit-Position: refs/heads/master@{#36822}
In a generator function, the parser rewrites a return statement into a "final"
yield. A final yield used to close the generator, which was incorrect because
the return may occur inside a try-finally clause and so the generator may not
yet terminate.
BUG=
Review URL: https://codereview.chromium.org/1634553002
Cr-Commit-Position: refs/heads/master@{#33537}
