Remove (untested) code for unsupported compilers.

src/utils.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_UTILS_H_
 #define V8_UTILS_H_
 
 #include <limits.h>
 #include <stdlib.h>
 #include <string.h>
@@ skipping 138 matching lines @@
 
 // Returns the absolute value of its argument.
 template <typename T>
 T Abs(T a) {
   return a < 0 ? -a : a;
 }
 
 
 // Floor(-0.0) == 0.0
 inline double Floor(double x) {
-#ifdef _MSC_VER
+#if V8_CC_MSVC
   if (x == 0) return x;  // Fix for issue 3477.
 #endif
   return std::floor(x);
 }
 
 
 // TODO(svenpanne) Clean up the whole power-of-2 mess.
 inline int32_t WhichPowerOf2Abs(int32_t x) {
   return (x == kMinInt) ? 31 : WhichPowerOf2(Abs(x));
 }
@@ skipping 1314 matching lines @@
   // Takes the address of the limit variable in order to find out where
   // the top of stack is right now.
   uintptr_t limit = reinterpret_cast<uintptr_t>(&limit);
   return limit;
 }
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_UTILS_H_