Fix Function.end_token_pos() and implement MethodMirror.source getter

runtime/lib/mirrors_impl.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.
 
 // VM-specific implementation of the dart:mirrors library.
 
 import "dart:collection";
 
 // These values are allowed to be passed directly over the wire.
 bool _isSimpleValue(var value) {
@@ skipping 998 matching lines @@
         } else if (parts.length == 2) {
           _constructorName = _s(parts[1]);
         } else {
           _constructorName = _s('');
         }
       }
     }
     return _constructorName;
   }
 
+  String _source = null;
+  String get source {
+    if (_source == null) {
+      _source = _MethodMirror_source(_reflectee);
+      assert(_source != null);
+    }
+    return _source;
+  }
+
   String toString() => "MethodMirror on '${_n(simpleName)}'";
 
   static dynamic _MethodMirror_owner(reflectee)
       native "MethodMirror_owner";
 
   static dynamic _MethodMirror_return_type(reflectee)
       native "MethodMirror_return_type";
 
   List<ParameterMirror> _MethodMirror_parameters(reflectee)
       native "MethodMirror_parameters";
+
+  static String _MethodMirror_source(reflectee)
+      native "MethodMirror_source";
 }
 
 class _LocalVariableMirrorImpl extends _LocalDeclarationMirrorImpl
     implements VariableMirror {
   _LocalVariableMirrorImpl(reflectee,
                            String simpleName,
                            this.owner,
                            this._type,
                            this.isStatic,
                            this.isFinal)
@@ skipping 180 matching lines @@
     if (typeMirror == null) {
       typeMirror = makeLocalTypeMirror(key);
       _instanitationCache[key] = typeMirror;
       if (typeMirror is ClassMirror && !typeMirror._isGeneric) {
         _declarationCache[key] = typeMirror;
       }
     }
     return typeMirror;
   }
 }