[PyTorch] Allow override for macro `HAS_DEMANGLE` (#66540)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/66540
Currently the macro `HAS_DEMANGLE` is determined by compiler predefined macros. Here I'm adding an option to allow `HAS_DEMANGLE` to be defined in build files.
Test Plan: Rely on CI
Reviewed By: poweic
Differential Revision: D31600007
fbshipit-source-id: 76cf088b0f5ee940e977d3b213f1446ea64be036
