Include XOP headers in clang-cl compatible way. Fix #1382.

PiperOrigin-RevId: 366463649
diff --git a/src/qs8-igemm/gen/4x4c2-minmax-xop-ld128.c b/src/qs8-igemm/gen/4x4c2-minmax-xop-ld128.c
index e6faba2..5b614fb 100644
--- a/src/qs8-igemm/gen/4x4c2-minmax-xop-ld128.c
+++ b/src/qs8-igemm/gen/4x4c2-minmax-xop-ld128.c
@@ -9,7 +9,7 @@
 
 #include <assert.h>
 
-#ifdef __GNUC__
+#if defined(__GNUC__) || defined(__clang__)
   #include <x86intrin.h>
 #else
   #include <immintrin.h>