Make frequent type checks (instanceof) faster by adding dedicated instanceof methods; improves dart…

runtime/lib/object_patch.dart

Index: runtime/lib/object_patch.dart
diff --git a/runtime/lib/object_patch.dart b/runtime/lib/object_patch.dart
index 52d7546a82d4e178b4ab752e3c8a11c835b0bad2..be42a57f618209d5770db07284128ffdb230745a 100644
--- a/runtime/lib/object_patch.dart
+++ b/runtime/lib/object_patch.dart
@@ -59,6 +59,12 @@ patch class Object {
                    bool negate)
       native "Object_instanceOf";
 
+  bool _instanceOfDouble(bool negate) native "Object_instanceOfDouble";
+  bool _instanceOfNum(bool negate) native "Object_instanceOfNum";
+  bool _instanceOfInt(bool negate) native "Object_instanceOfInt";
+  bool _instanceOfSmi(bool negate) native "Object_instanceOfSmi";
+  bool _instanceOfString(bool negate) native "Object_instanceOfString";
+
   // Call this function instead of inlining 'as', thus collecting type
   // feedback. Returns receiver.
   _as(instantiator, instantiator_type_arguments, type) native "Object_as";