[clang] [Modules] No transitive source location change (PR #86912)

[Rainer Orth via cfe-commits]

rorth wrote:

I strongly suspect that this patch badly broke the [Solaris/sparcv9 buildbot](https://lab.llvm.org/buildbot/#/builders/72/builds/4046): it introduced more than 1000 failures.

Please fix or revert.

https://github.com/llvm/llvm-project/pull/86912