Implement revised factories in the VM.

corelib/src/implementation/linked_hash_map.dart

Index: corelib/src/implementation/linked_hash_map.dart
===================================================================
--- corelib/src/implementation/linked_hash_map.dart	(revision 2391)
+++ corelib/src/implementation/linked_hash_map.dart	(working copy)
@@ -29,8 +29,7 @@
   }
 
   // See issue 417. Works in the vm, fails in dartc and frog.
-  factory LinkedHashMapImplementation/*<K extends Hashable, V>*/
-      .from(Map/*<K, V>*/ other) {
+  factory LinkedHashMapImplementation.from(Map/*<K, V>*/ other) {
     Map/*<K, V>*/ result = new LinkedHashMapImplementation/*<K, V>*/();
     other.forEach((/*K*/ key, /*V*/ value) { result[key] = value; });
     return result;