[clang] [clang][modules] Timestamp PCM files when writing (PR #112452)

[Volodymyr Sapsai via cfe-commits]

https://github.com/vsapsai commented:

I think the change makes sense. For example, for just-built .o files we assume they are valid and up-to-date, and don't need any extra verification.

As far as I understand, your change helps with the clean builds. And I believe incremental builds can still hit contention with updating timestamps (I can be wrong, though). Have you checked the performance for incremental builds?

https://github.com/llvm/llvm-project/pull/112452