[clang] [llvm] [clang][modules] Prevent deadlock in module cache (PR #182722)

[Shafik Yaghmour via cfe-commits]

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@@ -13,14 +13,18 @@
 #include "llvm/ADT/StringMap.h"
 
 #include <atomic>
+#include <condition_variable>
 #include <mutex>
-#include <shared_mutex>
 
 namespace clang {
 namespace dependencies {
 
 struct ModuleCacheEntry {
-  std::shared_mutex CompilationMutex;
+  std::mutex Mutex;
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shafik wrote:

ping, I think this got overshadowed by the other conversation

https://github.com/llvm/llvm-project/pull/182722