Linux create_sdk GN build for host

pkg/BUILD.gn

+# Copyright (c) 2016, 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("../utils/create_timestamp.gni")
+
+template("make_third_party_pkg_files_stamp") {
+  assert(defined(invoker.pattern), "Must define the file pattern")
+  assert(defined(invoker.id), "Must define the stamp file id")
+  path = rebase_path("../third_party/pkg")
+  if (defined(invoker.path)) {
+    path = invoker.path
+  }
+  id = invoker.id
+  create_timestamp_file(target_name) {
+    pattern = invoker.pattern
+    path = path
+    new_base = "//"
+    output = "$target_gen_dir/third_party_pkg_files_$id.stamp"
+  }
+}
+
+make_third_party_pkg_files_stamp("make_third_party_pkg_files_0_stamp") {
+  pattern = "^(?!.*/test/).*(?<!_test)[.]dart\$"
+  path = rebase_path(".")
+  id = "0"
+}
+
+make_third_party_pkg_files_stamp("make_third_party_pkg_files_1_stamp") {
+  pattern = "^(?!.*_test\.dart).*[a-k]\.dart\$"
+  id = "1"
+}
+
+make_third_party_pkg_files_stamp("make_third_party_pkg_files_2_stamp") {
+  pattern = "^(?!.*_test\.dart).*[l-r]\.dart\$"
+  id = "2"
+}
+
+make_third_party_pkg_files_stamp("make_third_party_pkg_files_3_stamp") {
+  pattern = "^(?!.*_test\.dart).*[^a-r]\.dart\$"
+  id = "3"
+}
+
+action("pkg_files_stamp") {
+  deps = [
+    ":make_third_party_pkg_files_0_stamp",
+    ":make_third_party_pkg_files_1_stamp",
+    ":make_third_party_pkg_files_2_stamp",
+    ":make_third_party_pkg_files_3_stamp",
+  ]
+
+  stamp0_outputs = get_target_outputs(":make_third_party_pkg_files_0_stamp")
+  stamp1_outputs = get_target_outputs(":make_third_party_pkg_files_1_stamp")
+  stamp2_outputs = get_target_outputs(":make_third_party_pkg_files_2_stamp")
+  stamp3_outputs = get_target_outputs(":make_third_party_pkg_files_3_stamp")
+
+  inputs = ["../tools/list_files.py"] +
+      stamp0_outputs +
+      stamp1_outputs +
+      stamp2_outputs +
+      stamp3_outputs
+
+  outputs = [
+    "$root_gen_dir/pkg_files.stamp"
+  ]
+
+  script = "../tools/create_timestamp_file.py"
+  args = [
+    rebase_path("$root_gen_dir/pkg_files.stamp"),
+  ]
+}