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

[David Stone via cfe-commits]

davidstone wrote:

Yes. Is there anything else you want to see in this PR before it can be merged? (I don't have merge permissions). This is the type of PR likely to get lots of conflicts if it stays open for long, so I'd like to get it wrapped up as fast as possible.

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