Workaround Python3.9 limitations in test_jit_py3 (#51088)
Summary:
In Python-3.9 and above `inspect.getsource` of a local class does not work if it was marked as default, see https://bugs.python.org/issue42666 https://github.com/pytorch/pytorch/issues/49617
Workaround by defining `make_global` function that programmatically accomplishes the same
Partially addresses issue raised in https://github.com/pytorch/pytorch/issues/49617
Pull Request resolved: https://github.com/pytorch/pytorch/pull/51088
Reviewed By: gmagogsfm
Differential Revision: D26069189
Pulled By: malfet
fbshipit-source-id: 7cf14b88ae5d2b95d2b0fd852717a9202b86356e
