[clang] [clang] Be const-correct with all uses of `Module *`. (PR #93493)

[Aaron Ballman via cfe-commits]

https://github.com/AaronBallman commented:

In general, I'm in favor of improving const-correctness like this. That said, I share the concerns of other reviewers that we should be sure we're adding const-correctness where it makes sense to do so. e.g., functions named `getSomething()` that return a pointer should probably be returning a const pointer. But for a function named `setSomething()` taking a pointer, it might not make sense to take a const pointer even if that's permissible currently.

https://github.com/llvm/llvm-project/pull/93493