Support argument definition test in constructors.

tests/language/argument_definition3_test.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.
+
+main() {
+  new Param.test1(false);
+  new Param.test1(true, 42);
+
+  new Param.test2(false);
+  new Param.test2(true, 42);
+
+  new Param.test3(false);
+  new Param.test3(true, 42);
+
+  new Param.test4();
+  new Param.test5();
+
+  new Param.test6(false);
+  new Param.test6(true, 42);
+
+  new Param.test7();
+  new Param.test8();
+}
+
+class Super {
+  var superField;
+  var otherSuperField;
+
+  Super();
+  Super.withParameters(passed, op, value) {
+    Expect.equals(passed, op);
+    Expect.equals(passed ? 42 : 0, value);
+  }
+
+  Super.withOptional(passed, [int a]) : superField = ?a {
+    Expect.equals(passed, ?a);
+    Expect.equals(passed, superField);
+  }
+
+  Super.withUpdate(passed, [int a = 0])
+      : superField = ?a, otherSuperField = a++ {
+    Expect.equals(passed, ?a);
+    Expect.equals(passed, superField);
+    Expect.equals(passed ? 43 : 1, a);
+  }
+}
+
+class Param extends Super {
+  var field;
+  var otherField;
+
+  Param.test1(a_check, [int a]) {
+    Expect.equals(a_check, ?a);
+  }
+
+  Param.test2(passed, [int a]) : field = ?a {
+    Expect.equals(passed, ?a);
+    Expect.equals(passed, field);
+  }
+
+  Param.test3(passed, [int a = 0]) : super.withParameters(passed, ?a, a) {
+    Expect.equals(passed, ?a);
+  }
+
+  Param.test4() : super.withOptional(true, 42);
+  Param.test5() : super.withOptional(false);
+
+  Param.test6(passed, [int a = 0]) : field = ?a, otherField = a++ {
+    Expect.equals(passed, ?a);
+    Expect.equals(passed, field);
+    Expect.equals(passed ? 43 : 1, a);
+  }
+
+  Param.test7() : super.withUpdate(true, 42);
+  Param.test8() : super.withUpdate(false);
+}