[clang] [Clang] Implement P3034R1 Module Declarations Shouldn’t be Macros (PR #90574)

[Davide Italiano via cfe-commits]

dcci wrote:

Code in question:
https://github.com/facebook/fbthrift/blob/ccfcd6743488c26d720bc4ff3348534491078b43/thrift/compiler/generate/t_py_generator.cc#L881

^ I am trying to find out a reduced testcase, but sending this here in case it rings a bell.

https://github.com/llvm/llvm-project/pull/90574