python 3.7 RecursionError when using recursive typing definition and get_type_hints #574
Description
The following code gives a RecursionError in python 3.7.0 (runs fine in 3.6.4, giving the answer {'return': typing.Sequence[typing.Union[str, typing.Sequence[typing.Union[str, _ForwardRef('Foo')]]]]})
import typing Foo = typing.Sequence[typing.Union[str, "Foo"]] def a() -> Foo: ... typing.get_type_hints(a)