Implement handlified String::Equals and Name::Equals.

src/ic.cc

Index: src/ic.cc
diff --git a/src/ic.cc b/src/ic.cc
index a00df8537c0724e5c1726d127f76641989809850..06e68ec091f083eaf8b99b1a08b31673cf5d0ad3 100644
--- a/src/ic.cc
+++ b/src/ic.cc
@@ -547,7 +547,7 @@ MaybeObject* LoadIC::Load(Handle<Object> object,
   if (FLAG_use_ic) {
     // Use specialized code for getting prototype of functions.
     if (object->IsJSFunction() &&
-        name->Equals(isolate()->heap()->prototype_string()) &&
+        String::Equals(isolate()->factory()->prototype_string(), name) &&
         Handle<JSFunction>::cast(object)->should_have_prototype()) {
       Handle<Code> stub;
       if (state() == UNINITIALIZED) {
@@ -889,13 +889,14 @@ Handle<Code> LoadIC::CompileHandler(LookupResult* lookup,
                                     Handle<String> name,
                                     Handle<Object> unused,
                                     InlineCacheHolderFlag cache_holder) {
-  if (object->IsString() && name->Equals(isolate()->heap()->length_string())) {
+  if (object->IsString() &&
+      String::Equals(isolate()->factory()->length_string(), name)) {
     int length_index = String::kLengthOffset / kPointerSize;
     return SimpleFieldLoad(length_index);
   }
 
   if (object->IsStringWrapper() &&
-      name->Equals(isolate()->heap()->length_string())) {
+      String::Equals(isolate()->factory()->length_string(), name)) {
     if (kind() == Code::LOAD_IC) {
       StringLengthStub string_length_stub;
       return string_length_stub.GetCode(isolate());
@@ -1213,7 +1214,7 @@ MaybeObject* StoreIC::Store(Handle<Object> object,
 
   // The length property of string values is read-only. Throw in strict mode.
   if (strict_mode() == STRICT && object->IsString() &&
-      name->Equals(isolate()->heap()->length_string())) {
+      String::Equals(isolate()->factory()->length_string(), name)) {
     return TypeError("strict_read_only_property", object, name);
   }
 
@@ -1400,7 +1401,7 @@ Handle<Code> StoreIC::CompileHandler(LookupResult* lookup,
         // properties. Slow properties might indicate redefinition of the length
         // property.
         if (receiver->IsJSArray() &&
-            name->Equals(isolate()->heap()->length_string()) &&
+            String::Equals(isolate()->factory()->length_string(), name) &&
             Handle<JSArray>::cast(receiver)->AllowsSetElementsLength() &&
             receiver->HasFastProperties()) {
           return compiler.CompileStoreArrayLength(receiver, lookup, name);