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

[Ian Anderson via cfe-commits]

ian-twilightcoder wrote:

> Ok _this_ one should fix the logic I think. @ilya-biryukov can you give this a try please?

@ilya-biryukov sorry to ping you again, just nobody else knows how to test this.

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