[clang] [X86] Add USER_MSR instructions. (PR #68944)

[Phoebe Wang via cfe-commits]

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@@ -20,6 +20,11 @@
 #include <uintrintrin.h>
 #endif
 
+#if !(defined(_MSC_VER) || defined(__SCE__)) || __has_feature(modules) ||      \
+    defined(__UINTR__)
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phoebewang wrote:

__USERMSR__

https://github.com/llvm/llvm-project/pull/68944