dart2js allocation tweaks

pkg/compiler/lib/src/io/location_provider.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.
 
 library dart2js.io.location_provider;
 
 import 'code_output.dart' show CodeOutputListener;
 
 import 'package:kernel/ast.dart' show Location, Source;
 
@@ skipping 21 matching lines @@
     length += text.length;
   }
 
   @override
   void onText(String text) {
     _collect(text);
   }
 
   @override
   Location getLocation(int offset) {
-    RangeError.checkValueInInterval(offset, 0, length, "offset",
-        "The value of 'offset' ($offset) must be between 0 and $length.");
+    RangeError.checkValueInInterval(offset, 0, length, 'offset');
     return new Source(lineStarts, null).getLocation(null, offset);
   }
 
   @override
   void onDone(int length) {
     lineStarts.add(length + 1);
     this.length = length;
   }
 
   String toString() {
     return 'lineStarts=$lineStarts,length=$length';
   }
 }