X64: Change strategy for spilling to match ia32. It's just better.

src/x64/assembler-x64.h

 // Copyright (c) 1994-2006 Sun Microsystems Inc.
 // 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.
 //
@@ skipping 481 matching lines @@
   // - Instructions on 32-bit (doubleword) operands/registers use 'l'.
   // - Instructions on 64-bit (quadword) operands/registers use 'q'.
   //
   // Some mnemonics, such as "and", are the same as C++ keywords.
   // Naming conflicts with C++ keywords are resolved by adding a trailing '_'.
 
   // Insert the smallest number of nop instructions
   // possible to align the pc offset to a multiple
   // of m. m must be a power of 2.
   void Align(int m);
+  // Aligns code to something that's optimal for a jump target for the platform.
+  void CodeTargetAlign();
 
   // Stack
   void pushfq();
   void popfq();
 
   void push(Immediate value);
   void push(Register src);
   void push(const Operand& src);
   void push(Label* label, RelocInfo::Mode relocation_mode);
 
@@ skipping 904 matching lines @@
  private:
   Assembler* assembler_;
 #ifdef DEBUG
   int space_before_;
 #endif
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_X64_ASSEMBLER_X64_H_