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 function expression, 'yield' is allowed, even if the expression
occurs inside a generator. Similarly, even in a non-generator,
a generator expression's name must not be 'yield'.
BUG=v8:3983
LOG=n
Review URL: https://codereview.chromium.org/1460393003
Cr-Commit-Position: refs/heads/master@{#32188}
