[clang] [clang] Store size & mtime in in-memory module cache (PR #190207)

[Cyndy Ishida via cfe-commits]

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@@ -1498,7 +1500,7 @@ static bool compileModuleImpl(CompilerInstance &ImportingInstance,
   Buffer = llvm::MemoryBuffer::getMemBufferCopy(ExtractedBuffer);
 
   ImportingInstance.getModuleCache().getInMemoryModuleCache().addBuiltPCM(
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cyndyishida wrote:

Not strictly related to the PR, but what is the benefit of exposing the `InMemoryModuleCache` to clients like `CompilerInstance`, `ASTReader`, `ModuleManager`? It seems like it would be easier to reason only about the `ModuleCache` at this scope.  FWIW, I also kind of similiarly about the `CompilerInstance` should not be responsible for updating the ModuleTimestamp.


https://github.com/llvm/llvm-project/pull/190207