[clang] [X86][Clang] Support constexpr evaluation of cvtpd2ps intrinsics (PR #169980)

[Hamza Hassanain via cfe-commits]

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@@ -207,9 +207,8 @@ _mm512_undefined(void)
   return (__m512)__builtin_ia32_undef512();
 }
 
-static __inline__ __m512 __DEFAULT_FN_ATTRS512
-_mm512_undefined_ps(void)
-{
+static __inline__ __m512 __DEFAULT_FN_ATTRS512_CONSTEXPR
+_mm512_undefined_ps(void) {
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HamzaHassanain wrote:

Ok, thanks for the clarifications! 

https://github.com/llvm/llvm-project/pull/169980