[clang] [Headers][X86] Enable constexpr handling for MMX/SSE/AVX/AVX512 PMADDWD/PMADDUBSW intrinsics (PR #161563)

[Bhasawut Singhaphan via cfe-commits]

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@@ -23,6 +23,9 @@
 
 #define __trunc64(x)                                                           \
   (__m64) __builtin_shufflevector((__v2di)(x), __extension__(__v2di){}, 0)
+#define __zext128(x)                                                           \
+  (__m128i) __builtin_shufflevector((__v2si)(x), __extension__(__v2si){}, 0,   \
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markbhasawut wrote:

Thanks for catching that!

https://github.com/llvm/llvm-project/pull/161563