Port improved ia32 CompareStub to x64. Add framework for inlined floating...

Port improved ia32 CompareStub to x64.  Add framework for inlined floating point compares, to be implemented in next change.
Review URL: http://codereview.chromium.org/1687014

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4515 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/x64/codegen-x64.h

@@ -488,6 +488,10 @@ class CodeGenerator: public AstVisitor {
                   Condition cc,
                   bool strict,
                   ControlDestination* destination);
+  void GenerateInlineNumberComparison(Result* left_side,
+                                      Result* right_side,
+                                      Condition cc,
+                                      ControlDestination* dest);
 
   // To prevent long attacker-controlled byte sequences, integer constants
   // from the JavaScript source are loaded in two parts if they are larger