Remove package root target and support scripts

pkg/pkg.gyp

-# 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.
-
-{
-  'targets': [
-    {
-      'target_name': 'pkg_packages',
-      'type': 'none',
-      'actions': [
-        {
-          'action_name': 'make_pkg_packages',
-          'inputs': [
-            '../tools/make_links.py',
-            '<!@(["python", "../tools/list_pkg_directories.py", "."])',
-            # Exclude DDC's old location in case folks didn't remove it.
-            '<!@(["python", "../tools/list_pkg_directories.py", '
-                '"../third_party/pkg", "--exclude=dev_compiler"])',
-            '<!@(["python", "../tools/list_pkg_directories.py", '
-                '"../third_party/pkg_tested"])',
-            '<!@(["python", "../tools/list_pkg_directories.py", '
-                '"../runtime"])',
-            '../sdk/lib/_internal/js_runtime/lib',
-            '../sdk/lib/_internal/sdk_library_metadata/lib',
-            '../third_party/observatory_pub_packages/packages/charted/lib',
-          ],
-          'outputs': [
-            '<(SHARED_INTERMEDIATE_DIR)/packages.stamp',
-            '<(PRODUCT_DIR)/.packages',
-          ],
-          'action': [
-            'python', '../tools/make_links.py', '--create-links',
-            '--create-package-file',
-            '--timestamp_file=<(SHARED_INTERMEDIATE_DIR)/packages.stamp',
-            '<(PRODUCT_DIR)',
-            '<@(_inputs)',
-            # Pub imports dart2js as compiler_unsupported so it can work outside
-            # the SDK. Map that to the compiler package.
-            'compiler/lib:compiler_unsupported'
-          ],
-        },
-      ],
-    }
-  ],
-}