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

[via cfe-commits]

yronglin wrote:

> I think the approach looks good.
> 
> Do we have existing tests for the use of `module` as an identifier outside of a module declaration?

IIUC, do you mean something looks like the following? I didn't find it in the test case:
```
void foo() {
  int module = 0;
}
```

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