Fix analyzer warnings in pkg/glob.

pkg/glob/lib/src/ast.dart

 // Copyright (c) 2014, 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.
 
 library glob.ast;
 
 import 'package:path/path.dart' as p;
 import 'package:collection/collection.dart';
 
 import 'utils.dart';
@@ skipping 280 matching lines @@
       buffer.write('-');
       buffer.write(regExpQuote(new String.fromCharCodes([range.max])));
     }
 
     buffer.write(']');
     return buffer.toString();
   }
 
   bool operator==(Object other) {
     if (other is! RangeNode) return false;
-    if (other.negated != negated) return false;
-    return const SetEquality().equals(ranges, other.ranges);
+    if ((other as RangeNode).negated != negated) return false;
+    return const SetEquality().equals(ranges, (other as RangeNode).ranges);
   }
 
   int get hashCode => (negated ? 1 : 3) * const SetEquality().hash(ranges);
 
   String toString() {
     var buffer = new StringBuffer()..write('[');
     for (var range in ranges) {
       buffer.writeCharCode(range.min);
       if (range.isSingleton) continue;
       buffer.write('-');
@@ skipping 50 matching lines @@
   LiteralNode(this.text, [this._context]);
 
   String _toRegExp() => regExpQuote(text);
 
   bool operator==(Object other) => other is LiteralNode && other.text == text;
 
   int get hashCode => text.hashCode;
 
   String toString() => text;
 }