Optimize AOT's switchable calls for the monomorphic case.

runtime/vm/assembler_x64.h

 // Copyright (c) 2013, 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_ASSEMBLER_X64_H_
 #define VM_ASSEMBLER_X64_H_
 
 #ifndef VM_ASSEMBLER_H_
 #error Do not include assembler_x64.h directly; use assembler.h instead.
 #endif
@@ skipping 931 matching lines @@
   //   ret PC
   //   .....
   // This code sets this up with the sequence:
   //   pushq rbp
   //   movq rbp, rsp
   //   pushq immediate(0)
   //   .....
   void EnterStubFrame();
   void LeaveStubFrame();
 
+  void RawEntry() { buffer_.Reset(); }
+  void NoMonomorphicCheckedEntry();
+  void MonomorphicCheckedEntry();
+
   void UpdateAllocationStats(intptr_t cid,
                              Heap::Space space);
 
   void UpdateAllocationStatsWithSize(intptr_t cid,
                                      Register size_reg,
                                      Heap::Space space);
   void UpdateAllocationStatsWithSize(intptr_t cid,
                                      intptr_t instance_size,
                                      Heap::Space space);
 
@@ skipping 203 matching lines @@
 }
 
 
 inline void Assembler::EmitOperandSizeOverride() {
   EmitUint8(0x66);
 }
 
 }  // namespace dart
 
 #endif  // VM_ASSEMBLER_X64_H_