FIx crash in disassembler: check that an addrs is tagged before testing it to be part of the heap.

runtime/vm/assembler_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"
 #if defined(TARGET_ARCH_X64)
 
 #include "vm/assembler.h"
 #include "vm/heap.h"
 #include "vm/memory_region.h"
@@ skipping 1513 matching lines @@
   }
   addq(RSP, Immediate(stack_elements * kWordSize));
 }
 
 
 void Assembler::LoadObject(Register dst, const Object& object) {
   if (object.IsSmi() || object.IsNull()) {
     movq(dst, Immediate(reinterpret_cast<int64_t>(object.raw())));
   } else {
     ASSERT(object.IsZoneHandle());
+    ASSERT(object.IsOld());
     AssemblerBuffer::EnsureCapacity ensured(&buffer_);
     EmitRegisterREX(dst, REX_W);
     EmitUint8(0xB8 | (dst & 7));
     buffer_.EmitObject(object);
   }
 }
 
 
 void Assembler::StoreObject(const Address& dst, const Object& object) {
   if (object.IsSmi() || object.IsNull()) {
     movq(dst, Immediate(reinterpret_cast<int64_t>(object.raw())));
   } else {
+    ASSERT(object.IsZoneHandle());
     ASSERT(object.IsOld());
     LoadObject(TMP, object);
     movq(dst, TMP);
   }
 }
 
 
 void Assembler::PushObject(const Object& object) {
   if (object.IsSmi() || object.IsNull()) {
     pushq(Immediate(reinterpret_cast<int64_t>(object.raw())));
@@ skipping 429 matching lines @@
 
 const char* Assembler::XmmRegisterName(XmmRegister reg) {
   ASSERT((0 <= reg) && (reg < kNumberOfXmmRegisters));
   return xmm_reg_names[reg];
 }
 
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_X64