Change List/Set/Map/Queue.from constructrs to accept any iterable.

sdk/lib/core/map.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.
 
 part of dart.core;
 
 /**
  * An collection of key-value pairs, from which you retrieve a value
  * using its associated key.
  *
@@ skipping 23 matching lines @@
    * A `LinkedHashMap` requires the keys to implement compatible
    * `operator==` and `hashCode`, and it allows null as a key.
    * It iterates in key insertion order.
    */
   factory Map() = LinkedHashMap<K, V>;
 
   /**
    * Creates a [LinkedHashMap] instance that contains all key-value pairs of
    * [other].
    *
+   * The keys must all be assignable to [K] and the values to [V].
+   * The [other] map itself can have any type.
+   *
    * A `LinkedHashMap` requires the keys to implement compatible
    * `operator==` and `hashCode`, and it allows null as a key.
    * It iterates in key insertion order.
    */
-  factory Map.from(Map<K, V> other) = LinkedHashMap<K, V>.from;
+  factory Map.from(Map other) = LinkedHashMap<K, V>.from;
 
   /**
    * Creates an identity map with the default implementation, [LinkedHashMap].
    *
    * The returned map allows `null` as a key.
    * It iterates in key insertion order.
    */
   factory Map.identity() = LinkedHashMap<K, V>.identity;
 
   /**
@@ skipping 183 matching lines @@
   /**
    * Returns true if there is no key-value pair in the map.
    */
   bool get isEmpty;
 
   /**
    * Returns true if there is at least one key-value pair in the map.
    */
   bool get isNotEmpty;
 }