Faster IC stubs by specializing them for Binary Smi operations

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/object.h"
 #include "vm/snapshot_ids.h"
 
 namespace dart {
 
 // Forward declarations.
 class Isolate;
 class ObjectPointerVisitor;
 
+// One-character symbols are added implicitly.
 #define PREDEFINED_SYMBOLS_LIST(V)                                             \
   V(Empty, "")                                                                 \
   V(EqualOperator, "==")                                                       \
   V(Identical, "identical")                                                    \
   V(Length, "length")                                                          \
   V(IndexToken, "[]")                                                          \
   V(AssignIndexToken, "[]=")                                                   \
   V(TopLevel, "::")                                                            \
   V(DefaultLabel, ":L")                                                        \
   V(This, "this")                                                              \
@@ skipping 498 matching lines @@
   friend class SnapshotReader;
   friend class SnapshotWriter;
   friend class ApiMessageReader;
 
   DISALLOW_COPY_AND_ASSIGN(Symbols);
 };
 
 }  // namespace dart
 
 #endif  // VM_SYMBOLS_H_