[clang] [Headers][X86] Allow AVX512 masked arithmetic ss/sd intrinsics to be used in constexpr (PR #162816)

[Simon Pilgrim via cfe-commits]

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@@ -3814,6 +3844,8 @@ __m128d test_mm_maskz_div_sd(__mmask8 __U, __m128d __A, __m128d __B) {
   // CHECK-NEXT: insertelement <2 x double> %{{.*}}, double %{{.*}}, i64 0
   return _mm_maskz_div_sd(__U,__A,__B); 
 }
+TEST_CONSTEXPR(match_m128d(_mm_maskz_div_sd(0x1, (__m128d)(__v2df){8.0, 10.0}, (__m128d)(__v2df){2.0, 20.0}), 4.0, 0.0));
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RKSimon wrote:

_mm_mask_move_ss / _mm_maskz_move_ss / _mm_mask_move_sd / _mm_maskz_move_sd test coverage

https://github.com/llvm/llvm-project/pull/162816