Don't use the size-zero array hack to access variable data in Snapshot.

runtime/vm/raw_object.h

 // 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.
 
 #ifndef VM_RAW_OBJECT_H_
 #define VM_RAW_OBJECT_H_
 
 #include "platform/assert.h"
 #include "vm/atomic.h"
 #include "vm/globals.h"
@@ skipping 209 matching lines @@
   private:                                                                     \
     RAW_OBJECT_IMPLEMENTATION(object);                                         \
     Raw##object* ptr() const {                                                 \
       ASSERT(IsHeapObject());                                                  \
       return reinterpret_cast<Raw##object*>(                                   \
           reinterpret_cast<uword>(this) - kHeapObjectTag);                     \
     }                                                                          \
     SNAPSHOT_WRITER_SUPPORT()                                                  \
     HEAP_PROFILER_SUPPORT()                                                    \
 
-#define OPEN_ARRAY_START(type, align)                                          \
-  do {                                                                         \
-    const uword result = reinterpret_cast<uword>(this) + sizeof(*this);        \
-    ASSERT(Utils::IsAligned(result, sizeof(align)));                           \
-    return reinterpret_cast<type*>(result);                                    \
-  } while (0)
-
 // RawObject is the base class of all raw objects, even though it carries the
 // class_ field not all raw objects are allocated in the heap and thus cannot
 // be dereferenced (e.g. RawSmi).
 class RawObject {
  public:
   // The tags field which is a part of the object header uses the following
   // bit fields for storing tags.
   enum TagBits {
     kWatchedBit = 0,
     kMarkBit = 1,
@@ skipping 1810 matching lines @@
   COMPILE_ASSERT(kExternalTypedDataInt8ArrayCid ==
                  kTypedDataInt8ArrayViewCid + 15);
   COMPILE_ASSERT(kByteBufferCid == kExternalTypedDataInt8ArrayCid + 14);
   COMPILE_ASSERT(kNullCid == kByteBufferCid + 1);
   return (kNullCid - kTypedDataInt8ArrayCid);
 }
 
 }  // namespace dart
 
 #endif  // VM_RAW_OBJECT_H_