Merge a few A64 utils into the CompilerIntrinsics.

src/a64/utils-a64.h

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 53 matching lines @@
 
 
 static inline double rawbits_to_double(uint64_t bits) {
   double value = 0.0;
   memcpy(&value, &bits, 8);
   return value;
 }
 
 
 // Bits counting.
-int CountLeadingZeros(uint64_t value, int width);
-int CountLeadingSignBits(int64_t value, int width);
-int CountTrailingZeros(uint64_t value, int width);
-int CountSetBits(uint64_t value, int width);
-int MaskToBit(uint64_t mask);
+inline int MaskToBit(uint64_t mask) {
+  ASSERT(CountSetBits(mask, 64) == 1);
+  return CountTrailingZeros(mask, 64);
+}
 
 
 // NaN tests.
 inline bool IsSignallingNaN(double num) {
   const uint64_t kFP64QuietNaNMask = 0x0008000000000000UL;
   uint64_t raw = double_to_rawbits(num);
   if (std::isnan(num) && ((raw & kFP64QuietNaNMask) == 0)) {
     return true;
   }
   return false;
@@ skipping 11 matching lines @@
 
 
 template <typename T>
 inline bool IsQuietNaN(T num) {
   return std::isnan(num) && !IsSignallingNaN(num);
 }
 
 } }  // namespace v8::internal
 
 #endif  // V8_A64_UTILS_A64_H_