[clang] [Modules] Detect ODR mismatches for enums in non-C++ like in C++. (PR #90298)

[Volodymyr Sapsai via cfe-commits]

vsapsai wrote:

In C++ we reject mismatched types coming from different Clang modules. Haven't checked the behavior for C++20 modules as I'm not changing it.

In C modules aren't a part of any standard as far as I know. But for Clang modules we reject most of the mismatched types coming from different modules. The current change extends the set of "most of the mismatched types" to include enums.

https://github.com/llvm/llvm-project/pull/90298