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

runtime/vm/disassembler_arm64.cc

Index: runtime/vm/disassembler_arm64.cc
diff --git a/runtime/vm/disassembler_arm64.cc b/runtime/vm/disassembler_arm64.cc
index a2386412d3080adc9fbb6c0c241b02db4486a2dc..dd7d00c3d1c170080f91f8888a413a1587576554 100644
--- a/runtime/vm/disassembler_arm64.cc
+++ b/runtime/vm/disassembler_arm64.cc
@@ -7,6 +7,7 @@
 #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 {
 
@@ -1488,7 +1489,8 @@ void ARM64Decoder::InstructionDecode(uword pc) {
 
 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();
@@ -1496,6 +1498,14 @@ void Disassembler::DecodeInstruction(char* hex_buffer, intptr_t hex_size,
   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