Port optimization of comparison with a trivial LHS from ia32 to x64.

Review URL: http://codereview.chromium.org/2868028

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4943 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/x64/codegen-x64.cc

@@ -3855,8 +3855,17 @@ void CodeGenerator::VisitCompareOperation(CompareOperation* node) {
     default:
       UNREACHABLE();
   }
-  Load(left);
-  Load(right);
+
+  if (left->IsTrivial()) {
+    Load(right);
+    Result right_result = frame_->Pop();
+    frame_->Push(left);
+    frame_->Push(&right_result);
+  } else {
+    Load(left);
+    Load(right);
+  }
+
   Comparison(node, cc, strict, destination());
 }