Do not rely on code patching on DBC for lazy deoptimization.

runtime/vm/code_patcher_x64.cc

 // 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.
 
 #include "vm/globals.h"  // Needed here to get TARGET_ARCH_X64.
 #if defined(TARGET_ARCH_X64)
 
 #include "vm/assembler.h"
 #include "vm/code_patcher.h"
 #include "vm/cpu.h"
@@ skipping 260 matching lines @@
   }
   return call.target();
 }
 
 
 intptr_t CodePatcher::InstanceCallSizeInBytes() {
   return InstanceCall::kCallPatternSize;
 }
 
 
-void CodePatcher::InsertDeoptimizationCallAt(uword start) {
-  UNREACHABLE();
-}
-
-
 RawFunction* CodePatcher::GetUnoptimizedStaticCallAt(uword return_address,
                                                      const Code& code,
                                                      ICData* ic_data_result) {
   ASSERT(code.ContainsInstructionAt(return_address));
   UnoptimizedStaticCall static_call(return_address, code);
   ICData& ic_data = ICData::Handle();
   ic_data ^= static_call.ic_data();
   if (ic_data_result != NULL) {
     *ic_data_result = ic_data.raw();
   }
@@ skipping 44 matching lines @@
                                       NativeFunction* target) {
   ASSERT(code.ContainsInstructionAt(return_address));
   NativeCall call(return_address, code);
   *target = call.native_function();
   return call.target();
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_X64