[compiler-rt] [compiler-rt][builtins] Add opt-in pthread_mutex_t locks to libatomic (PR #95326)

[via llvm-commits]

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@@ -237,6 +237,14 @@ if(NOT FUCHSIA AND NOT COMPILER_RT_BAREMETAL_BUILD)
   )
 endif()
 
+option(COMPILER_RT_LIBATOMIC_USE_PTHREAD
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Logikable wrote:

We can try to switch that after this PR lands.

https://github.com/llvm/llvm-project/pull/95326