[HEAP] Remove SIMD 128 bit alignment from heap.

src/snapshot/deserializer.h

 // Copyright 2016 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_SNAPSHOT_DESERIALIZER_H_
 #define V8_SNAPSHOT_DESERIALIZER_H_
 
 #include "src/heap/heap.h"
 #include "src/objects.h"
 #include "src/snapshot/serializer-common.h"
@@ skipping 66 matching lines @@
   bool ReserveSpace();
 
   void UnalignedCopy(Object** dest, Object** src) {
     memcpy(dest, src, sizeof(*src));
   }
 
   void SetAlignment(byte data) {
     DCHECK_EQ(kWordAligned, next_alignment_);
     int alignment = data - (kAlignmentPrefix - 1);
     DCHECK_LE(kWordAligned, alignment);
-    DCHECK_LE(alignment, kSimd128Unaligned);

[Yang, 2017/02/14 21:32:00]

please do not remove this check, but rather change the upper bound to
kDoubleUnaligned.

[bbudge, 2017/02/14 22:18:51]

Good catch. Put it back.

     next_alignment_ = static_cast<AllocationAlignment>(alignment);
   }
 
   void DeserializeDeferredObjects();
   void DeserializeInternalFields(
       v8::DeserializeInternalFieldsCallback internal_fields_deserializer);
 
   void FlushICacheForNewIsolate();
   void FlushICacheForNewCodeObjectsAndRecordEmbeddedObjects();
 
@@ skipping 50 matching lines @@
 
   AllocationAlignment next_alignment_;
 
   DISALLOW_COPY_AND_ASSIGN(Deserializer);
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_SNAPSHOT_DESERIALIZER_H_