Use memmove instead of a loop to read bytes.

vm/snapshot.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_SNAPSHOT_H_
 #define VM_SNAPSHOT_H_
 
 #include "platform/assert.h"
 #include "vm/allocation.h"
 #include "vm/bitfield.h"
@@ skipping 172 matching lines @@
     static T Read(ReadStream* st) {
       return bit_cast<T>(st->Read<int64_t>());
     }
   };
 
   uint8_t ReadByte() {
     ASSERT(current_ < end_);
     return *current_++;
   }
 
+  void ReadBytes(uint8_t* addr, intptr_t len) {
+    ASSERT((current_ + len) < end_);
+    memmove(addr, current_, len);
+    current_ += len;
+  }
+
  private:
   const uint8_t* buffer_;
   const uint8_t* current_;
   const uint8_t* end_;
 
   // SnapshotReader needs access to the private Raw classes.
   friend class SnapshotReader;
   friend class BaseReader;
   DISALLOW_COPY_AND_ASSIGN(ReadStream);
 };
@@ skipping 110 matching lines @@
     return ReadStream::Raw<sizeof(T), T>::Read(&stream_);
   }
 
   // Reads an intptr_t type value.
   intptr_t ReadIntptrValue() {
     int64_t value = Read<int64_t>();
     ASSERT((value <= kIntptrMax) && (value >= kIntptrMin));
     return value;
   }
 
+  void ReadBytes(uint8_t* addr, intptr_t len) {
+    stream_.ReadBytes(addr, len);
+  }
+
   RawSmi* ReadAsSmi();
   intptr_t ReadSmiValue();
 
  private:
   ReadStream stream_;  // input stream.
 };
 
 
 // Reads a snapshot into objects.
 class SnapshotReader : public BaseReader {
@@ skipping 231 matching lines @@
 
  private:
   SnapshotWriter* writer_;
 
   DISALLOW_COPY_AND_ASSIGN(SnapshotWriterVisitor);
 };
 
 }  // namespace dart
 
 #endif  // VM_SNAPSHOT_H_