Correct some return types in itertools.pyi from Iterable to Iterator. (#947)
Correct some return types in itertools.pyi from Iterable to Iterator. (#947)

* Fix a few return types in stdlib/2/inspect.pyi.

* Rename _FrameRecord to _FrameInfo

* Correct some return types in itertools.pyi from Iterable to Iterator.

euresti/typeshed,li-dan/typeshed,azag0/typeshed