[clang] [Headers][X86] Allow SSE41/AVX2/AVX512F/AVX512BW integer extension intrinsics to be used in constexpr (PR #152971)

[via cfe-commits]

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@@ -27,6 +27,12 @@
                  __min_vector_width__(128)))
 #endif
 
+#if defined(__cplusplus) && (__cplusplus >= 201103L)
+#define __DEFAULT_FN_ATTRS_CONSTEXPR __DEFAULT_FN_ATTRS constexpr
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woruyu wrote:

Done!

https://github.com/llvm/llvm-project/pull/152971