[X86] Remove unnecessary MMX declarations from Intrin.h

[RKSimon]

Summary

As discussed in PR23648 - the intrinsics _m_from_int, _m_to_int and _m_prefetch are defined in mmintrin.h and prfchwintrin.h so we don't need to in Intrin.h

Added tests for _m_from_int and _m_to_int

D11338 already added a test for _m_prefetch

I'll add _m_from_float and _m_to_float in a future (3dNow) patch which will remove the last of the 'missing' declarations from Intrin.h

cfe/trunk/lib/Headers/Intrin.h

 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
 #if defined(__MMX__)
 /* And the random ones that aren't in those files. */
 __m64 _m_from_float(float);
-__m64 _m_from_int(int _l);
-void _m_prefetch(void *);
 float _m_to_float(__m64);
-int _m_to_int(__m64 _M);
 #endif
 
 /* Other assorted instruction intrinsics. */
 void __addfsbyte(unsigned long, unsigned char);
 void __addfsdword(unsigned long, unsigned long);
 void __addfsword(unsigned long, unsigned short);
 void __code_seg(const char *);
 static __inline__

cfe/trunk/test/CodeGen/mmx-builtins.c

__m64 test88(__m64 a, __m64 b) {
   // CHECK: pcmpgtw
   return _mm_cmpgt_pi16(a, b);
 }
 
 __m64 test89(__m64 a, __m64 b) {
   // CHECK: pcmpgtd
   return _mm_cmpgt_pi32(a, b);
 }
+
+__m64 test90(int a) {
+  // CHECK: movd
+  return _m_from_int(a);
+}
+
+int test91(__m64 a) {
+  // CHECK: movd
+  return _m_to_int(a);
+}