Properly detect name collisions at library level

tests/language/src/ToplevelCollision2Test.dart

Index: tests/language/src/ToplevelCollision2Test.dart
===================================================================
--- tests/language/src/ToplevelCollision2Test.dart	(revision 0)
+++ tests/language/src/ToplevelCollision2Test.dart	(revision 0)
@@ -0,0 +1,20 @@
+// 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.
+
+
+get x() => 200;
+
+// Ok: can have a setter named x when getter x is defined.
+set x(var i) { print(i); }

[srdjan, 2011/11/30 00:37:35]

Add:
/// 02: continued

so that there is a version that passes.

[hausner, 2011/11/30 18:52:48]

Doesn't work that way, apparently. Omitting as per our discussion.

+
+// Error: there is already a getter for x
+int x;                          /// 00: compile-time error
+
+// Error: there is already a getter named x.
+int x(a, b) { print(a + b); }   /// 01: compile-time error
+
+
+void main() {
+  // No need to reference x.
+}