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

[Cyndy Ishida via cfe-commits]

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@@ -28,16 +28,24 @@ namespace clang {
 /// each \a ModuleManager sees the same files.
 class InMemoryModuleCache : public llvm::RefCountedBase<InMemoryModuleCache> {
   struct PCM {
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cyndyishida wrote:

That makes sense. Could you update the doc comment to remove `implicit` in this case? 

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