X64: Implement debugger hooks.

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 425 matching lines @@
   void GetCode(CodeDesc* desc);
 
   // Read/Modify the code target in the branch/call instruction at pc.
   // On the x64 architecture, the address is absolute, not relative.
   static inline Address target_address_at(Address pc);
   static inline void set_target_address_at(Address pc, Address target);
 
   // Distance between the address of the code target in the call instruction
   // and the return address.  Checked in the debug build.
   static const int kTargetAddrToReturnAddrDist = 3 + kPointerSize;
-
+  // Distance between start of patched return sequence and the emitted address
+  // to jump to.
+  static const int kReturnAddrPatchPrefixSize = 2;  // movq = REX.W 0xB8+r.
 
   // ---------------------------------------------------------------------------
   // Code generation
   //
   // Function names correspond one-to-one to x64 instruction mnemonics.
   // Unless specified otherwise, instructions operate on 64-bit operands.
   //
   // If we need versions of an assembly instruction that operate on different
   // width arguments, we add a single-letter suffix specifying the width.
   // This is done for the following instructions: mov, cmp, inc, dec,
@@ skipping 453 matching lines @@
   // Call near indirect
   void call(const Operand& operand);
 
   // Jumps
   // Jump short or near relative.
   void jmp(Label* L);  // unconditional jump to L
 
   // Jump near absolute indirect (r64)
   void jmp(Register adr);
 
+  // Jump near absolute indirect (m64)
+  void jmp(const Operand& src);
+
   // Conditional jumps
   void j(Condition cc, Label* L);
 
   // Floating-point operations
   void fld(int i);
 
   void fld1();
   void fldz();
 
   void fld_s(const Operand& adr);
@@ skipping 355 matching lines @@
  private:
   Assembler* assembler_;
 #ifdef DEBUG
   int space_before_;
 #endif
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_X64_ASSEMBLER_X64_H_