[clang] [Clang] VectorExprEvaluator::VisitCallExpr / InterpretBuiltin - add MMX/SSE/AVX/AVX512 PMULHRSW intrinsics to be used in constexpr (PR #160636)

[Simon Pilgrim via cfe-commits]

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

undef this at the end of the file

https://github.com/llvm/llvm-project/pull/160636