[clang] [clang][modules] HeaderSearch::MarkFileModuleHeader creates extra HeaderFileInfo, breaks PCM reuse (PR #89005)

[Ilya Biryukov via cfe-commits]

ilya-biryukov wrote:

> @ilya-biryukov can you check that this fixes your running out of source location space problem please?

Just tried it. The patch as is did not help.
I've also tried changing the previous line to `getExistingFileInfo(, /*WantExternal=*/false)` and it didn't help either.

Changing from `if ((Role & ModuleMap::ExcludedHeader))` back to `if (!ModuleMap::isModular(Role))` does help, though, but that clearly leads to an incorrect behavior as far as the code is concerned.

https://github.com/llvm/llvm-project/pull/89005