Finish refactoring done for ia32 for the other platforms.

src/x64/lithium-x64.h

Index: src/x64/lithium-x64.h
===================================================================
--- src/x64/lithium-x64.h	(revision 11389)
+++ src/x64/lithium-x64.h	(working copy)
@@ -212,8 +212,8 @@
   virtual void CompileToNative(LCodeGen* generator) = 0;
   virtual const char* Mnemonic() const = 0;
   virtual void PrintTo(StringStream* stream);
-  virtual void PrintDataTo(StringStream* stream) = 0;
-  virtual void PrintOutputOperandTo(StringStream* stream) = 0;
+  virtual void PrintDataTo(StringStream* stream);
+  virtual void PrintOutputOperandTo(StringStream* stream);
 
   enum Opcode {
     // Declare a unique enum value for each instruction.
@@ -308,9 +308,6 @@
   int TempCount() { return T; }
   LOperand* TempAt(int i) { return temps_[i]; }
 
-  virtual void PrintDataTo(StringStream* stream);
-  virtual void PrintOutputOperandTo(StringStream* stream);
-
  protected:
   EmbeddedContainer<LOperand*, R> results_;
   EmbeddedContainer<LOperand*, I> inputs_;