[clang] [ASTWriter] Detect more non-affecting FileIDs to reduce source location duplication (PR #112015)

[Ilya Biryukov via cfe-commits]

ilya-biryukov wrote:

This is a change that should remove the need for a hack from #88893, reaching the same effect while keeping the command-line interface as it is today.


https://github.com/llvm/llvm-project/pull/112015