Fix Function.end_token_pos() and implement MethodMirror.source getter

tests/lib/mirrors/method_mirror_source_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.
+
+import "dart:mirrors";
+
+import "package:expect/expect.dart";
+
+expectSource(Mirror mirror, String source) {
+  if (mirror is ClosureMirror) {
+    mirror = mirror.function;
+  }
+  Expect.isTrue(mirror is MethodMirror);
+  Expect.equals(mirror.source, source);
+}
+
+foo1() {}
+
+int get x => 42;
+set x(value) { }
+
+class S {}
+
+class C extends S {
+
+  var _x;
+  var _y;
+
+  C(this.x, y)
+    : _y = y,
+      super();
+
+  factory C.other(num z) {}
+  factory C.other2() {}
+  factory C.other3() = C.other2;
+
+  static dynamic foo() {
+    // Happy foo.
+  }
+
+  // Some comment.
+
+  void bar() { /* Not so happy bar. */ }
+
+  num get someX =>
+    181;
+
+  set someX(v) {
+    // Discard this one.
+  }
+}
+    
+
+main() {
+  // Top-level members
+  LibraryMirror lib = reflectClass(C).owner;
+  expectSource(lib.members[const Symbol("foo1")],
+      "foo1() {}");
+  expectSource(lib.members[const Symbol("x")],
+      "int get x => 42;");
+  expectSource(lib.members[const Symbol("x=")],
+      "set x(value) { }");
+
+  // Class members
+  ClassMirror cm = reflectClass(C);
+  expectSource(cm.members[const Symbol("foo")],
+      "static dynamic foo() {\n"
+      "    // Happy foo.\n"
+      "  }");
+  expectSource(cm.members[const Symbol("bar")],
+      "void bar() { /* Not so happy bar. */ }");
+  expectSource(cm.members[const Symbol("someX")],
+      "num get someX =>\n"
+      "    181;");
+  expectSource(cm.members[const Symbol("someX=")],
+      "set someX(v) {\n"
+      "    // Discard this one.\n"
+      "  }");
+  expectSource(cm.constructors[const Symbol("C")],
+      "C(this.x, y)\n"
+      "    : _y = y,\n"
+      "      super();");
+  expectSource(cm.constructors[const Symbol("C.other")],
+      "factory C.other(num z) {}");
+  expectSource(cm.constructors[const Symbol("C.other3")],
+      "factory C.other3() = C.other2;");
+
+  // Closures
+  expectSource(reflect((){}), "(){}");
+  expectSource(reflect((x,y,z) { return x*y*z; }), "(x,y,z) { return x*y*z; }");
+  expectSource(reflect((e) => doSomething(e)), "(e) => doSomething(e)");
+
+  namedClosure(x,y,z) => 1;
+  var a = () {};
+  expectSource(reflect(namedClosure), "namedClosure(x,y,z) => 1;");
+  expectSource(reflect(a), "() {}");
+}