[clang] [clang][modules] Dependency Scanning: Temporarily Turn Off Negative Directory Caching (PR #134698)

[Qiongsi Wu via cfe-commits]

qiongsiwu wrote:

> AFAICT that patch special-cased for framework directories while this one disables much more. Is that not the case?

Oh sorry I misspoke - it is not the case that skipping framework negative caching that fixed the problem. It is the _other_ case in `shouldCacheStatFailures` that was causing the problem, namely, the case where the extension is empty. When I applied https://github.com/swiftlang/llvm-project/pull/9076/ for testing I added `shouldCacheStatFailures` back, which included the directory caching part. So it was not correct to say that https://github.com/swiftlang/llvm-project/pull/9076/ fixed the problem, but rather, an older compiler never had the problem because it did not have https://github.com/llvm/llvm-project/commit/55323ca6c8b9d21d85591f3499b299b62463321f. In other words, it seems that https://github.com/llvm/llvm-project/commit/55323ca6c8b9d21d85591f3499b299b62463321f is the commit that caused the build failure. 

https://github.com/llvm/llvm-project/pull/134698