Implement ParameterMirror.metadata.

tests/lib/mirrors/parameter_metadata_test.dart

+// 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.
+
+library test.parameter_metadata_test;
+
+import 'dart:mirrors';
+
+import 'metadata_test.dart';
+
+const m1 = 'm1';
+const m2 = const Symbol('m2');
+const m3 = const CustomAnnotation(3);
+
+class CustomAnnotation {
+  final value;
+  const CustomAnnotation(this.value);
+  toString() => 'CustomAnnotation($value)';
+}
+
+class B {
+  B.foo(int x);
+  factory B.bar(@m3 @m2 int z, x){}
+
+  baz(@m1 final int x, @m2 int y, @m3 final int z);
+  qux(int x, [@m3 @m2 @m1 int y= 3 + 1]);
+  quux(int x, {String str: "foo"});
+  corge({@m1 int x: 3 * 17, @m2 String str: "bar"});
+
+  set x(@m2 final value);
+}
+
+main() {
+  ClassMirror cm = reflectClass(B);
+
+  checkMetadata(cm.constructors[const Symbol('B.foo')].parameters[0], []);
+
+  checkMetadata(cm.constructors[const Symbol('B.bar')].parameters[0], [m3, m2]);
+  checkMetadata(cm.constructors[const Symbol('B.bar')].parameters[1], []);
+
+  checkMetadata(cm.members[const Symbol('baz')].parameters[0], [m1]);
+  checkMetadata(cm.members[const Symbol('baz')].parameters[1], [m2]);
+  checkMetadata(cm.members[const Symbol('baz')].parameters[2], [m3]);
+
+  checkMetadata(cm.members[const Symbol('qux')].parameters[0], []);
+  checkMetadata(cm.members[const Symbol('qux')].parameters[1], [m3, m2, m1]);
+
+  checkMetadata(cm.members[const Symbol('quux')].parameters[0], []);
+  checkMetadata(cm.members[const Symbol('quux')].parameters[1], []);
+
+  checkMetadata(cm.members[const Symbol('corge')].parameters[0], [m1]);
+  checkMetadata(cm.members[const Symbol('corge')].parameters[1], [m2]);
+
+  checkMetadata(cm.members[const Symbol('x=')].parameters[0], [m2]);
+}