[clang] [clang][modules] Print library module manifest path. (PR #76451)

[Boris Kolpackov via cfe-commits]

boris-kolpackov wrote:

> I had looked at `-print-search-dirs` but it seems buggy. For example, it ignores the `-stdlib` flag to the compiler invocation. 

True. I couldn't find a bug report for this so I filed one: https://github.com/llvm/llvm-project/issues/76614

> Solving this seems a lot of work. So didn't want to add new features to that code.

If this is the right thing to do (i.e., printing this information as part of `-print-search-dirs`), then perhaps it's still worth it to try and fix? Once you add a separate option, you will have to drag it forever (for backwards compatibility).

https://github.com/llvm/llvm-project/pull/76451