[runtime] Replace the EQUALS builtin with proper Object::Equals.

src/runtime/runtime-object.cc

Index: src/runtime/runtime-object.cc
diff --git a/src/runtime/runtime-object.cc b/src/runtime/runtime-object.cc
index 75d09a8ee70598931332ce4213b161fba036244c..0c6f81306ee7981c98a5d4150aa0e3d8879105e7 100644
--- a/src/runtime/runtime-object.cc
+++ b/src/runtime/runtime-object.cc
@@ -1478,6 +1478,18 @@ RUNTIME_FUNCTION(Runtime_ToName) {
 }
 
 
+RUNTIME_FUNCTION(Runtime_Equals) {
+  HandleScope scope(isolate);
+  DCHECK_EQ(2, args.length());
+  CONVERT_ARG_HANDLE_CHECKED(Object, x, 0);
+  CONVERT_ARG_HANDLE_CHECKED(Object, y, 1);
+  Maybe<bool> result = Object::Equals(x, y);
+  if (!result.IsJust()) return isolate->heap()->exception();
+  // TODO(bmeurer): Change this at some point to return true/false instead.
+  return Smi::FromInt(result.FromJust() ? EQUAL : NOT_EQUAL);
+}
+
+
 RUNTIME_FUNCTION(Runtime_StrictEquals) {
   SealHandleScope scope(isolate);
   DCHECK_EQ(2, args.length());