Sped up hashCode by removing megamorphic call to _identityHashCode.

runtime/vm/bootstrap_natives.h

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef VM_BOOTSTRAP_NATIVES_H_
 #define VM_BOOTSTRAP_NATIVES_H_
 
 #include "vm/native_entry.h"
 
 // bootstrap dart natives used in the core dart library.
 
 namespace dart {
 
 // List of bootstrap native entry points used in the core dart library.
 #define BOOTSTRAP_NATIVE_LIST(V)                                               \
   V(DartCore_fatal, 1)                                                         \
   V(Object_equals, 2)                                                          \
   V(Object_getHash, 1)                                                         \
   V(Object_setHash, 2)                                                         \
   V(Object_toString, 1)                                                        \
   V(Object_noSuchMethod, 6)                                                    \
   V(Object_runtimeType, 1)                                                     \
   V(Object_instanceOf, 4)                                                      \
+  V(Object_simpleInstanceOf, 2)                                                \
   V(Object_instanceOfNum, 2)                                                   \
   V(Object_instanceOfInt, 2)                                                   \
   V(Object_instanceOfSmi, 2)                                                   \
   V(Object_instanceOfDouble, 2)                                                \
   V(Object_instanceOfString, 2)                                                \
   V(Object_as, 3)                                                              \
   V(Function_apply, 2)                                                         \
   V(Closure_equals, 2)                                                         \
   V(Closure_hashCode, 1)                                                       \
   V(Closure_clone, 1)                                                          \
@@ skipping 400 matching lines @@
 #ifndef PRODUCT
   MIRRORS_BOOTSTRAP_NATIVE_LIST(DECLARE_BOOTSTRAP_NATIVE)
 #endif
 
 #undef DECLARE_BOOTSTRAP_NATIVE
 };
 
 }  // namespace dart
 
 #endif  // VM_BOOTSTRAP_NATIVES_H_