Move Iterable implementation to collection.

sdk/lib/_internal/compiler/implementation/scanner/byte_strings.dart

 // Copyright (c) 2011, 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.
 
 /**
  * An abstract string representation.
  */
-abstract class ByteString extends Iterable<int> implements SourceString {
+abstract class ByteString extends IterableBase<int> implements SourceString {
   final List<int> bytes;
   final int offset;
   final int length;
   int _hashCode;
 
   ByteString(List<int> this.bytes, int this.offset, int this.length);
 
   String get charset;
 
   String slowToString() => new String.fromCharCodes(
@@ skipping 126 matching lines @@
  * A ByteString-valued token.
  */
 class ByteStringToken extends Token {
   final ByteString value;
 
   ByteStringToken(PrecedenceInfo info, ByteString this.value, int charOffset)
     : super(info, charOffset);
 
   String toString() => value.toString();
 }