Revert "Add List.first."

runtime/lib/growable_array.dart

 // 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.
 
 class _GrowableObjectArray<T> implements List<T> {
   factory _GrowableObjectArray._uninstantiable() {
     throw new UnsupportedError(
         "GrowableObjectArray can only be allocated by the VM");
   }
 
@@ skipping 127 matching lines @@
   }
 
   T removeLast() {
     var len = length - 1;
     var elem = this[len];
     this[len] = null;
     _setLength(len);
     return elem;
   }
 
-  T get first {
-    return this[0];
-  }
-
   T get last {
     return this[length - 1];
   }
 
   int indexOf(T element, [int start = 0]) {
     return Arrays.indexOf(this, element, start, length);
   }
 
   int lastIndexOf(T element, [int start = null]) {
     if (start == null) start = length - 1;
@@ skipping 54 matching lines @@
   }
 
   String toString() {
     return Collections.collectionToString(this);
   }
 
   Iterator<T> iterator() {
     return new SequenceIterator<T>(this);
   }
 }