[runtime] Replace COMPARE/COMPARE_STRONG with proper Object::Compare.

src/full-codegen/full-codegen.cc

Index: src/full-codegen/full-codegen.cc
diff --git a/src/full-codegen/full-codegen.cc b/src/full-codegen/full-codegen.cc
index e889185571d4e8e38a997bbb05d2f401f7f60855..ea53844fbfc3dc9eb89dd3296cd8c72e3dc8e04e 100644
--- a/src/full-codegen/full-codegen.cc
+++ b/src/full-codegen/full-codegen.cc
@@ -498,19 +498,6 @@ void FullCodeGenerator::EmitMathPow(CallRuntime* expr) {
 }
 
 
-void FullCodeGenerator::EmitStringCompare(CallRuntime* expr) {
-  ZoneList<Expression*>* args = expr->arguments();
-  DCHECK_EQ(2, args->length());
-
-  VisitForStackValue(args->at(0));
-  VisitForStackValue(args->at(1));
-
-  StringCompareStub stub(isolate());
-  __ CallStub(&stub);
-  context()->Plug(result_register());
-}
-
-
 bool RecordStatementPosition(MacroAssembler* masm, int pos) {
   if (pos == RelocInfo::kNoPosition) return false;
   masm->positions_recorder()->RecordStatementPosition(pos);