Fix unaligned access to TypedData from native code.

tests/language/vm/unaligned_access_register_index_test.dart

-// Copyright (c) 2016, 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.
-// VMOptions=--optimization_counter_threshold=10 --no-background_compilation
-
-import 'dart:typed_data';
-import 'package:expect/expect.dart';
-
-unalignedUint16() {
-  var bytes = new ByteData(64);
-  for (var i = 0; i < 2; i++) {
-    bytes.setUint16(i, 0xABCD);
-    Expect.equals(0xABCD, bytes.getUint16(i));
-  }
-}
-
-unalignedInt16() {
-  var bytes = new ByteData(64);
-  for (var i = 0; i < 2; i++) {
-    bytes.setInt16(i, -0x1234);
-    Expect.equals(-0x1234, bytes.getInt16(i));
-  }
-}
-
-unalignedUint32() {
-  var bytes = new ByteData(64);
-  for (var i = 0; i < 4; i++) {
-    bytes.setUint32(i, 0xABCDABCD);
-    Expect.equals(0xABCDABCD, bytes.getUint32(i));
-  }
-}
-
-unalignedInt32() {
-  var bytes = new ByteData(64);
-  for (var i = 0; i < 4; i++) {
-    bytes.setInt32(i, -0x12341234);
-    Expect.equals(-0x12341234, bytes.getInt32(i));
-  }
-}
-
-unalignedUint64() {
-  var bytes = new ByteData(64);
-  for (var i = 0; i < 8; i++) {
-    bytes.setUint64(i, 0xABCDABCD);
-    Expect.equals(0xABCDABCD, bytes.getUint64(i));
-  }
-}
-
-unalignedInt64() {
-  var bytes = new ByteData(64);
-  for (var i = 0; i < 8; i++) {
-    bytes.setInt64(i, -0x12341234);
-    Expect.equals(-0x12341234, bytes.getInt64(i));
-  }
-}
-
-unalignedFloat32() {
-  var bytes = new ByteData(64);
-  for (var i = 0; i < 4; i++) {
-    bytes.setFloat32(i, 16.25);
-    Expect.equals(16.25, bytes.getFloat32(i));
-  }
-}
-
-unalignedFloat64() {
-  var bytes = new ByteData(64);
-  for (var i = 0; i < 8; i++) {
-    bytes.setFloat64(i, 16.25);
-    Expect.equals(16.25, bytes.getFloat64(i));
-  }
-}
-
-main() {
-  for (var i = 0; i < 20; i++) {
-    unalignedUint16();
-    unalignedInt16();
-    unalignedUint32();
-    unalignedInt32();
-    unalignedUint64();
-    unalignedInt64();
-    unalignedFloat32();
-    unalignedFloat64();
-  }
-}