Adds debugger patching to arm64.

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 26 matching lines @@
                                        intptr_t* value);
 
   // Decodes a load sequence ending at 'end' (the last instruction of the
   // load sequence is the instruction before the one at end).  Returns the
   // address of the first instruction in the sequence.  Returns the register
   // being loaded and the index in the pool being read from in the output
   // parameters 'reg' and 'index' respectively.
   static uword DecodeLoadWordFromPool(uword end,
                                       Register* reg,
                                       intptr_t* index);
+
+  // Encodes a load sequence ending at 'end'. Encodes a fixed length two
+  // instruction load from the pool pointer in PP using the destination
+  // register reg as a temporary for the base address.
+  static void EncodeLoadWordFromPoolFixed(uword end, int32_t offset);
+
+  static intptr_t OffsetFromPPIndex(intptr_t index);
 };
 
 
 class CallPattern : public ValueObject {
  public:
   CallPattern(uword pc, const Code& code);
 
   RawICData* IcData();
   RawArray* ClosureArgumentsDescriptor();
 
@@ skipping 37 matching lines @@
 
  private:
   const uword pc_;
 
   DISALLOW_COPY_AND_ASSIGN(JumpPattern);
 };
 
 }  // namespace dart
 
 #endif  // VM_INSTRUCTIONS_ARM64_H_