Revert "Remove V8_HOST_CAN_READ_UNALIGNED and its uses."

src/snapshot-source-sink.cc

 // Copyright 2014 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.
 
 
 #include "src/snapshot-source-sink.h"
 
 #include "src/base/logging.h"
 #include "src/handles-inl.h"
 #include "src/serialize.h"  // for SerializerDeserializer::nop() in AtEOF()
 
 
 namespace v8 {
 namespace internal {
 
 
 SnapshotByteSource::SnapshotByteSource(const byte* array, int length)
     : data_(array), length_(length), position_(0) {
 }
 
 
 SnapshotByteSource::~SnapshotByteSource() { }
 
 
 int32_t SnapshotByteSource::GetUnalignedInt() {
   DCHECK(position_ < length_);  // Require at least one byte left.
+#if defined(V8_HOST_CAN_READ_UNALIGNED) &&  __BYTE_ORDER == __LITTLE_ENDIAN
+  int32_t answer = *reinterpret_cast<const int32_t*>(data_ + position_);
+#else
   int32_t answer = data_[position_];
   answer |= data_[position_ + 1] << 8;
   answer |= data_[position_ + 2] << 16;
   answer |= data_[position_ + 3] << 24;
+#endif
   return answer;
 }
 
 
 void SnapshotByteSource::CopyRaw(byte* to, int number_of_bytes) {
   MemCopy(to, data_ + position_, number_of_bytes);
   position_ += number_of_bytes;
 }
 
 
@@ skipping 47 matching lines @@
 }
 
 
 void DebugSnapshotSink::Put(byte b, const char* description) {
   PrintF("%24s: %x\n", description, b);
   sink_->Put(b, description);
 }
 
 }  // namespace v8::internal
 }  // namespace v8