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

[Mark de Wever via cfe-commits]

mordante wrote:

> LGTM.
> 
> We need to delete `clang/test/Driver/Inputs/cxx23_modules/usr/lib/x86_64-linux-gnu/libc++.so` and `clang/test/Driver/Inputs/cxx23_modules/usr/lib/x86_64-linux-gnu/modules.json`, we should generate them with `split-file`

Are you sure that is the proper way? Should these tests not use a complete installation to make sure it works on installations?

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