Optimize AOT's switchable calls for the monomorphic case.

runtime/vm/assembler_arm64.h

 // Copyright (c) 2014, 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_ARM64_H_
 #define VM_ASSEMBLER_ARM64_H_
 
 #ifndef VM_ASSEMBLER_H_
 #error Do not include assembler_arm64.h directly; use assembler.h instead.
 #endif
@@ skipping 470 matching lines @@
 
   RawObjectPool* MakeObjectPool() {
     return object_pool_wrapper_.MakeObjectPool();
   }
 
   bool use_far_branches() const {
     return FLAG_use_far_branches || use_far_branches_;
   }
 
   void set_use_far_branches(bool b) {
-    ASSERT(buffer_.Size() == 0);
     use_far_branches_ = b;
   }
 
   void FinalizeInstructions(const MemoryRegion& region) {
     buffer_.FinalizeInstructions(region);
   }
 
   // Debugging and bringup support.
   void Stop(const char* message);
   void Unimplemented(const char* message);
@@ skipping 855 matching lines @@
 
   void EnterCallRuntimeFrame(intptr_t frame_size);
   void LeaveCallRuntimeFrame();
   void CallRuntime(const RuntimeEntry& entry, intptr_t argument_count);
 
   // Set up a stub frame so that the stack traversal code can easily identify
   // a stub frame.
   void EnterStubFrame();
   void LeaveStubFrame();
 
+  void NoMonomorphicCheckedEntry();
+  void MonomorphicCheckedEntry();
+
   void UpdateAllocationStats(intptr_t cid,
                              Heap::Space space);
 
   void UpdateAllocationStatsWithSize(intptr_t cid,
                                      Register size_reg,
                                      Heap::Space space);
 
   // If allocation tracing for |cid| is enabled, will jump to |trace| label,
   // which will allocate in the runtime where tracing occurs.
   void MaybeTraceAllocation(intptr_t cid,
@@ skipping 574 matching lines @@
                                   Register value,
                                   Label* no_update);
 
   DISALLOW_ALLOCATION();
   DISALLOW_COPY_AND_ASSIGN(Assembler);
 };
 
 }  // namespace dart
 
 #endif  // VM_ASSEMBLER_ARM64_H_