[clang] [X86][Clang] Allow SSE/AVX COMI/UCOMI/CMPS/CMPP fp comparison intrinsics to be used in constexpr (PR #160876)

[Simon Pilgrim via cfe-commits]

================
@@ -36,6 +36,7 @@
 #include "ByteCode/Frame.h"
 #include "ByteCode/State.h"
 #include "ExprConstShared.h"
+#include "immintrin.h"
----------------
RKSimon wrote:

don't do this - it can fail on non-x86 builds - just use the raw encodings and add a /*_CMP_EQ_OQ*/ style comment

https://github.com/llvm/llvm-project/pull/160876