Use the Code's pointer offsets to find object references when disassembling IA32.

runtime/vm/disassembler_arm64.cc

 // 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.
 
 #include "vm/disassembler.h"
 
 #include "vm/globals.h"  // Needed here to get TARGET_ARCH_ARM64.
 #if defined(TARGET_ARCH_ARM64)
 #include "platform/assert.h"
+#include "vm/instructions.h"
 
 namespace dart {
 
 #ifndef PRODUCT
 
 class ARM64Decoder : public ValueObject {
  public:
   ARM64Decoder(char* buffer, size_t buffer_size)
       : buffer_(buffer),
         buffer_size_(buffer_size),
@@ skipping 1461 matching lines @@
   } else if (instr->IsDPSimd2Op()) {
     DecodeDPSimd2(instr);
   } else {
     Unknown(instr);
   }
 }
 
 
 void Disassembler::DecodeInstruction(char* hex_buffer, intptr_t hex_size,
                                      char* human_buffer, intptr_t human_size,
-                                     int* out_instr_size, uword pc) {
+                                     int* out_instr_size, const Code& code,
+                                     Object** object, uword pc) {
   ARM64Decoder decoder(human_buffer, human_size);
   decoder.InstructionDecode(pc);
   int32_t instruction_bits = Instr::At(pc)->InstructionBits();
   OS::SNPrint(hex_buffer, hex_size, "%08x", instruction_bits);
   if (out_instr_size) {
     *out_instr_size = Instr::kInstrSize;
   }
+
+  *object = NULL;
+  if (!code.IsNull()) {
+    *object = &Object::Handle();
+    if (!DecodeLoadObjectFromPoolOrThread(pc, code, *object)) {
+      *object = NULL;
+    }
+  }
 }
 
 #endif  // !PRODUCT
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM