Issue 1091: Static type warning for setters with non-void return types

tests/language/src/Setter3Test.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.
+
+// Test that setters cannot have defined, non-void return types.
+// Note: The language specification specifies the absence of a type means
+// it is dynamic, however you cannot specify dynamic.
+
+class A {
+  set foo(x) {}
+  void set bar(x) {}
+  Dynamic set baz(x) {} /// 01: static type error
+  bool set bob(x) {} /// 02: static type error
+}
+
+main() {
+  new A();
+}