Detect illegal assignable expressions

tests/language/assignable_expression_test.dart

Index: tests/language/assignable_expression_test.dart
===================================================================
--- tests/language/assignable_expression_test.dart	(revision 0)
+++ tests/language/assignable_expression_test.dart	(working copy)
@@ -0,0 +1,44 @@
+// Copyright (c) 2013, 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 to detect syntactically illegal left-hand-side (assignable)
+// expressions.
+
+class C {
+  static var static_field = 0;
+}
+
+var tl_static_var = 0;
+
+main() {
+  tl_static_var = 0;
+  (tl_static_var) = 0;    /// 01: compile-time error
+  (tl_static_var)++;      /// 02: compile-time error
+  ++(tl_static_var);      /// 03: compile-time error
+
+  C.static_field = 0;
+  (C.static_field) = 0;   /// 11: compile-time error
+  (C.static_field)++;     /// 12: compile-time error
+  ++(C.static_field);     /// 13: compile-time error
+
+  tl_static_var = [1, 2, 3];
+  tl_static_var[0] = 0;
+  (tl_static_var)[0] = 0;
+  (tl_static_var[0]) = 0;    /// 21: compile-time error
+  (tl_static_var[0])++;      /// 22: compile-time error
+  ++(tl_static_var[0]);      /// 23: compile-time error
+
+  C.static_field = [1, 2, 3];
+  (C.static_field[0]) = 0;   /// 31: compile-time error
+  (C.static_field[0])++;     /// 32: compile-time error
+  ++(C.static_field[0]);     /// 33: compile-time error
+
+  var a = 0;
+  (a) = 0;   /// 41: compile-time error
+  (a)++;     /// 42: compile-time error
+  ++(a);     /// 43: compile-time error
+
+  // Neat palindrome expression. x is assignable, ((x)) is not.
+  var funcnuf = (x) => ((x))=((x)) <= (x);  /// 50: compile-time error
+}