mypy

28f92aca - Don't expand global variables in body of a function with constrained type variables (#9882)

Don't expand global variables in body of a function with constrained type variables (#9882) See first test case for the scenario where this causes issues (the second test case is already handled elsewhere and just added for completeness). This is an old issue, but it is important to fix it now because recent changes to PEP 484 about re-export force people to use function aliases. Co-authored-by: Ivan Levkivskyi <ilevkivskyi@dropbox.com>