remove docgen source and targets from build

pkg/docgen/test/multi_library_code/lib/test_lib_foo.dart

Index: pkg/docgen/test/multi_library_code/lib/test_lib_foo.dart
diff --git a/pkg/docgen/test/multi_library_code/lib/test_lib_foo.dart b/pkg/docgen/test/multi_library_code/lib/test_lib_foo.dart
deleted file mode 100644
index b615bf60a85e19a29c90c7d4c925a624a9a7e133..0000000000000000000000000000000000000000
--- a/pkg/docgen/test/multi_library_code/lib/test_lib_foo.dart
+++ /dev/null
@@ -1,41 +0,0 @@
-// Copyright (c) 2014, 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_lib.foo;
-
-import 'test_lib.dart';
-
-/**
- * Doc comment for class [B].
- *
- * Multiline Test
- */
-
-/*
- * Normal comment for class B.
- */
-class B extends A {
-
-  B();
-  B.fooBar();
-
-  /**
-   * Test for linking to super
-   */
-  int doElse(int b) {
-    print(b);
-    return b;
-  }
-
-  /**
-   * Test for linking to parameter [c]
-   */
-  void doThis(int c) {
-    print(c);
-  }
-}
-
-int testFunc(int a) {
-  return a;
-}