Fix parsing of subscript expressions using python resolver (#39269)
Summary:
- add call out to python resolver in parseArgsFromDecl, parserReturnFromDecl
- add support in python resolver for nested subexpressions
- wrap python resolver call in exception handling to fall back to c++ path
- add tests for newly resolvable types
- closes https://github.com/pytorch/pytorch/issues/38728
Fixes bug where SourceRange objects did not include the final closing ']' for a subscript expression. E.g. range for 'List[int]' previously included only 'List[int'.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/39269
Differential Revision: D21956402
Pulled By: wconstab
fbshipit-source-id: 5d783260322eb1e04e20bc931a8e9d9179765f13
