Cycles Refactor: Add SSE Utility code from Embree for cleaner SSE code.

This makes the code a bit easier to understand, and might come in handy
if we want to reuse more Embree code.

Differential Revision: https://developer.blender.org/D482

Code by Brecht, with fixes by Lockal, Sergey and myself.

intern/cycles/util/util_optimization.h

@@ -101,6 +101,10 @@
 /* SSE intrinsics headers */
 #ifndef FREE_WINDOWS64
 
+#ifdef _MSC_VER
+#include <intrin.h>
+#else
+
 #ifdef __KERNEL_SSE2__
 #include <xmmintrin.h> /* SSE 1 */
 #include <emmintrin.h> /* SSE 2 */
@@ -118,6 +122,12 @@
 #include <smmintrin.h> /* SSE 4.1 */
 #endif
 
+#ifdef __KERNEL_AVX__
+#include <immintrin.h> /* AVX */
+#endif
+
+#endif
+
 #else
 
 /* MinGW64 has conflicting declarations for these SSE headers in <windows.h>.