Make first and last getters.

lib/compiler/implementation/source_file.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('source_file');
 
 #import('dart:math');
 
 #import('colors.dart', prefix: 'colors');
 
@@ skipping 22 matching lines @@
         starts.add(index);
       }
       starts.add(text.length + 1);
       _lineStarts = starts;
     }
     return _lineStarts;
   }
 
   int getLine(int position) {
     List<int> starts = lineStarts;
-    if (position < 0 || starts.last() <= position) {
+    if (position < 0 || starts.last <= position) {
       throw 'bad position #$position in file $filename with '
             'length ${text.length}.';
     }
     int first = 0;
     int count = starts.length;
     while (count > 1) {
       int step = count ~/ 2;
       int middle = first + step;
       int lineStart = starts[middle];
       if (position < lineStart) {
@@ skipping 42 matching lines @@
       }
 
       for (; i < toColumn; i++) {
         buf.add(color('^'));
       }
     }
 
     return buf.toString();
   }
 }