Revert 428. Breaks 64-bit compilation.

src/globals.h

 // Copyright 2006-2008 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 445 matching lines @@
 #ifdef __GNUC__
 #if (__GNUC__ >= 4)
 #define INLINE(header) inline header  __attribute__((always_inline))
 #else
 #define INLINE(header) inline __attribute__((always_inline)) header
 #endif
 #else
 #define INLINE(header) inline header
 #endif
 
-// The type-based aliasing rule allows the compiler to assume that pointers of
-// different types (for some definition of different) never alias each other.
-// Thus the following code does not work:
-//
-// float f = foo();
-// int fbits = *(int*)(&f);
-//
-// The compiler 'knows' that the int pointer can't refer to f since the types
-// don't match, so the compiler may cache f in a register, leaving random data
-// in fbits.  Using C++ style casts makes no difference, however a pointer to
-// char data is assumed to alias any other pointer.  This is the 'memcpy
-// exception'.
-//
-// Bit_cast uses the memcpy exception to move the bits from a variable of one
-// type o a variable of another type.  Of course the end result is likely to
-// be implementation dependent.  Most compilers (gcc-4.2 and MSVC 2005)
-// will completely optimize bit_cast away.
-//
-// There is an additional use for bit_cast.
-// Recent gccs will warn when they see casts that may result in breakage due to
-// the type-based aliasing rule.  If you have checked that there is no breakage
-// you can use bit_cast to cast one pointer type to another.  This confuses gcc
-// enough that it can no longer see that you have cast one pointer type to
-// another thus avoiding the warning.
-template <class Dest, class Source>
-inline Dest bit_cast(const Source& source) {
-  // Compile time assertion: sizeof(Dest) == sizeof(Source)
-  // A compile error here means your Dest and Source have different sizes.
-  typedef char VerifySizesAreEqual[sizeof(Dest) == sizeof(Source) ? 1 : -1];
-
-  Dest dest;
-  memcpy(&dest, &source, sizeof(dest));
-  return dest;
-}
-
-
 } }  // namespace v8::internal
 
 #endif  // V8_GLOBALS_H_