Implement argument definition test in the vm.

tests/language/argument_definition_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.
+// Dart test program for testing argument definition test.
+
+int test(int a, [int b, int c]) {
+  int result = 0;
+  ?b;
+  ?result;  /// 01: compile-time error
+  if (?a) {
+    result += 100;
+  }
+  if (?b) {
+    result += 20;
+  }
+  if (?c) {
+    var b; ?b;  /// 02: compile-time error
+    result += 3;
+  }
+  return result;
+}
+
+closure_test(int a, [int b, int c]) {
+  var x = 0;
+  return () {
+    int result = 0;
+    ?b;
+    ?result;  /// 03: compile-time error
+    ?x;  /// 04: compile-time error
+    if (?a) {
+      result += 100;
+    }
+    if (?b) {
+      result += 20;
+    }
+    if (?c) {
+      var b; ?b;  /// 05: compile-time error
+      result += 3;
+    }
+    return result;
+  };
+}
+
+main() {
+  // Use a loop to test optimized version as well.
+  for (int i = 0; i < 1000; i++) {
+    Expect.equals(100, test(1));
+    Expect.equals(120, test(1, 2));
+    Expect.equals(123, test(1, 2, 3));
+    Expect.equals(103, test(1, c:3));
+
+    Expect.equals(100, closure_test(1)());
+    Expect.equals(120, closure_test(1, 2)());
+    Expect.equals(123, closure_test(1, 2, 3)());
+    Expect.equals(103, closure_test(1, c:3)());
+  }
+}