Revert "Move Arrays class to private library."

runtime/lib/simd128.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.
 
 patch class Float32x4 {
   /* patch */ factory Float32x4(double x, double y, double z, double w) {
     return new _Float32x4(x, y, z, w);
   }
   /* patch */ factory Float32x4.zero() {
     return new _Float32x4.zero();
@@ skipping 595 matching lines @@
     return result;
   }
   void setRange(int start, int length, List<Float32x4> from,
                 [int startFrom = 0]) {
     if (from is _Float32x4Array) {
       _setRange(start * _BYTES_PER_ELEMENT,
                 length * _BYTES_PER_ELEMENT,
                 from,
                 startFrom * _BYTES_PER_ELEMENT);
     } else {
-      IterableMixinWorkaround.setRangeList(
-          this, start, length, from, startFrom);
+      Arrays.copy(from, startFrom, this, start, length);
     }
   }
   String toString() {
     return Collections.collectionToString(this);
   }
   int bytesPerElement() {
     return _BYTES_PER_ELEMENT;
   }
   int lengthInBytes() {
     return _length() * _BYTES_PER_ELEMENT;
@@ skipping 41 matching lines @@
 
   List<Float32x4> getRange(int start, int length) {
     _rangeCheck(this.length, start, length);
     List<Float32x4> result = new Float32List(length);
     result.setRange(0, length, this, start);
     return result;
   }
 
   void setRange(int start, int length, List<Float32x4> from,
                [int startFrom = 0]) {
-    IterableMixinWorkaround.setRangeList(this, start, length, from, startFrom);
+    Arrays.copy(from, startFrom, this, start, length);
   }
 
   String toString() {
     return Collections.collectionToString(this);
   }
 
   int bytesPerElement() {
     return _BYTES_PER_ELEMENT;
   }
 
@@ skipping 35 matching lines @@
   }
 
   void setRange(int start, int length, List<Float32x4> from,
                 [int startFrom = 0]) {
     if (from is _ExternalFloat32x4Array) {
       _setRange(start * _BYTES_PER_ELEMENT,
                 length * _BYTES_PER_ELEMENT,
                 from,
                 startFrom * _BYTES_PER_ELEMENT);
     } else {
-      IterableMixinWorkaround.setRangeList(
-          this, start, length, from, startFrom);
+      Arrays.copy(from, startFrom, this, start, length);
     }
   }
 
   String toString() {
     return Collections.collectionToString(this);
   }
 
   int bytesPerElement() {
     return _BYTES_PER_ELEMENT;
   }
 
   int lengthInBytes() {
     return _length() * _BYTES_PER_ELEMENT;
   }
 
   static const int _BYTES_PER_ELEMENT = 16;
 
   Float32x4 _getIndexed(int index)
       native "ExternalFloat32x4Array_getIndexed";
   int _setIndexed(int index, Float32x4 value)
       native "ExternalFloat32x4Array_setIndexed";
 }