Revert "Lazy deopt without code patching."

runtime/vm/instructions_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.
 // Classes that describe assembly patterns as used by inline caches.
 
 #ifndef VM_INSTRUCTIONS_ARM64_H_
 #define VM_INSTRUCTIONS_ARM64_H_
 
 #ifndef VM_INSTRUCTIONS_H_
 #error Do not include instructions_arm64.h directly; use instructions.h instead.
@@ skipping 46 matching lines @@
 
 class CallPattern : public ValueObject {
  public:
   CallPattern(uword pc, const Code& code);
 
   RawICData* IcData();
 
   RawCode* TargetCode() const;
   void SetTargetCode(const Code& target) const;
 
+  // This constant length is only valid for inserted call patterns used for
+  // lazy deoptimization. Regular call pattern may vary in length.
+  static const int kDeoptCallLengthInInstructions = 5;
+  static const int kDeoptCallLengthInBytes =
+      kDeoptCallLengthInInstructions * Instr::kInstrSize;
+
+  static void InsertDeoptCallAt(uword pc, uword target_address);
+
  private:
   const ObjectPool& object_pool_;
 
   uword end_;
   uword ic_data_load_end_;
 
   intptr_t target_code_pool_index_;
   ICData& ic_data_;
 
   DISALLOW_COPY_AND_ASSIGN(CallPattern);
@@ skipping 57 matching lines @@
 
   bool IsValid() const;
 
  private:
   const uword pc_;
 };
 
 }  // namespace dart
 
 #endif  // VM_INSTRUCTIONS_ARM64_H_