- Fix use of String operator + in language and corelib tests.

tests/language/src/CallThroughGetterTest.dart

 // Copyright (c) 2011, 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.
 
 // Tests that we can call functions through getters.
 
 final TOP_LEVEL_CONST = 1;
 final TOP_LEVEL_CONST_REF = TOP_LEVEL_CONST;
 final TOP_LEVEL_NULL = null;
 
@@ skipping 93 matching lines @@
     b = new B();
     Expect.equals("yzxgf", b.g3(b.y, b.z, b.x));
     b = new B();
     Expect.equals("gyzxf", (b.g3)(b.y, b.z, b.x));
   }
 
   static void expectThrowsNotClosure(fn) {
     var exception = catchException(fn);
     if (!(exception is ObjectNotClosureException)) {
       Expect.fail("Wrong exception.  Expected: ObjectNotClosureException"
-          + " got: ${exception}");
+          " got: ${exception}");
     }
   }
 
   static catchException(fn) {
     bool caught = false;
     var result = null;
     try {
       fn();
       Expect.equals(true, false);  // Shouldn't reach this.
     } catch (var e) {
@@ skipping 23 matching lines @@
 
   get g0() { _mark('g'); return f0() { return _mark('f'); }; }
   get g1() { _mark('g'); return f1(x) { return _mark('f'); }; }
   get g2() { _mark('g'); return f2(x, y) { return _mark('f'); }; }
   get g3() { _mark('g'); return f3(x, y, z) { return _mark('f'); }; }
 
   get x() { _mark('x'); return 0; }
   get y() { _mark('y'); return 1; }
   get z() { _mark('z'); return 2; }
 
-  _mark(m) { _order += m; return _order; }
+  _mark(m) { _order = _order.concat(m); return _order; }

[kasperl, 2012/03/12 06:55:42]

This would be cleaner with a string buffer, but I understand if you don't want
to mess too much with this test.

Pretty sure something like:

   _order.add(m); return _order.toString()

would work fine if you change _order to a StringBuffer.

[Ivan Posva, 2012/04/11 14:26:00]

Done.

   String _order;
 
 }
 
 main() {
   CallThroughGetterTest.testMain();
 }