[clang] [clang] Canonicalizing `-include-pch` input in the Frontend (PR #180065)

[Jan Svoboda via cfe-commits]

================
@@ -1040,7 +1049,7 @@ bool FrontendAction::BeginSourceFile(CompilerInstance &CI,
                 CI.getPCHContainerReader(), CI.getLangOpts(),
                 CI.getCodeGenOpts(), CI.getTargetOpts(),
                 CI.getPreprocessorOpts(), CI.getHeaderSearchOpts(),
-                SpecificModuleCachePath,
+                CI.getSpecificModuleCachePath(),
----------------
jansvoboda11 wrote:

This recomputes the context hash for each file in the directory. Why is that necessary?

https://github.com/llvm/llvm-project/pull/180065