Move js library back into compiler directory.

sdk/lib/_internal/compiler/js_lib/typed_data_patch.dart

 // Copyright (c) 2013, 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.
 
 
 import 'dart:_internal' show FixedLengthListMixin;
 import 'dart:_foreign_helper' show JS;
 import 'dart:math' as Math;
 import 'dart:_internal';
 import 'dart:_interceptors' show JSIndexable, JSUInt32, JSUInt31;
@@ skipping 138 matching lines @@
       NativeInt32x4.fromFloat32x4Bits;
 }
 
 @patch class Float64x2 {
   @patch factory Float64x2(double x, double y) = NativeFloat64x2;
   @patch factory Float64x2.splat(double v) = NativeFloat64x2.splat;
   @patch factory Float64x2.zero() = NativeFloat64x2.zero;
   @patch factory Float64x2.fromFloat32x4(Float32x4 v) =
       NativeFloat64x2.fromFloat32x4;
 }