Sped up hashCode by removing megamorphic call to _identityHashCode.

runtime/vm/symbols.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_SYMBOLS_H_
 #define VM_SYMBOLS_H_
 
 #include "vm/growable_array.h"
 #include "vm/object.h"
 #include "vm/snapshot_ids.h"
@@ skipping 293 matching lines @@
   V(SpaceWhereNewLine, " where\n")                                             \
   V(SpaceIsFromSpace, " is from ")                                             \
   V(InTypeCast, " in type cast")                                               \
   V(TypeQuote, "type '")                                                       \
   V(QuoteIsNotASubtypeOf, "' is not a subtype of ")                            \
   V(SpaceOfSpace, " of ")                                                      \
   V(SwitchExpr, ":switch_expr")                                                \
   V(TwoNewlines, "\n\n")                                                       \
   V(TwoSpaces, "  ")                                                           \
   V(_instanceOf, "_instanceOf")                                                \
+  V(_simpleInstanceOf, "_simpleInstanceOf")                                    \
+  V(_simpleInstanceOfTrue, "_simpleInstanceOfTrue")                            \
+  V(_simpleInstanceOfFalse, "_simpleInstanceOfFalse")                          \
   V(_instanceOfSmi, "_instanceOfSmi")                                          \
   V(_instanceOfNum, "_instanceOfNum")                                          \
   V(_instanceOfInt, "_instanceOfInt")                                          \
   V(_instanceOfDouble, "_instanceOfDouble")                                    \
   V(_instanceOfString, "_instanceOfString")                                    \
   V(_as, "_as")                                                                \
   V(GetterPrefix, "get:")                                                      \
   V(ClosurizePrefix, "get:#")                                                  \
   V(SetterPrefix, "set:")                                                      \
   V(InitPrefix, "init:")                                                       \
@@ skipping 355 matching lines @@
   friend class Serializer;
   friend class Deserializer;
   friend class ApiMessageReader;
 
   DISALLOW_COPY_AND_ASSIGN(Symbols);
 };
 
 }  // namespace dart
 
 #endif  // VM_SYMBOLS_H_