Attempt to fix Win32 build by avoiding a compiler intrinsic.

TBR=mstarzinger@chromium.org
Review URL: https://chromiumcodereview.appspot.com/10198020

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@11428 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/compiler-intrinsics.h

@@ -76,11 +76,6 @@ int CompilerIntrinsics::CountLeadingZeros(uint32_t value) {
 }
 
 int CompilerIntrinsics::CountSetBits(uint32_t value) {
-  // __popcnt is only supported from VS2008.
-#define _MSC_VER_VS2008 1500
-#if _MSC_VER >= _MSC_VER_VS2008
-  return __popcnt(value);
-#else
   // Manually count set bits.
   value = ((value >>  1) & 0x55555555) + (value & 0x55555555);
   value = ((value >>  2) & 0x33333333) + (value & 0x33333333);
@@ -88,8 +83,6 @@ int CompilerIntrinsics::CountSetBits(uint32_t value) {
   value = ((value >>  8) & 0x00ff00ff) + (value & 0x00ff00ff);
   value = ((value >> 16) & 0x0000ffff) + (value & 0x0000ffff);
   return value;
-#endif
-#undef _MSC_VER_VS2008
 }
 
 #else