Use native async/await support in pub.

sdk/lib/_internal/pub_generated/test/dart2js/source_maps_include_core_libs_test.dart

Index: sdk/lib/_internal/pub_generated/test/dart2js/source_maps_include_core_libs_test.dart
diff --git a/sdk/lib/_internal/pub_generated/test/dart2js/source_maps_include_core_libs_test.dart b/sdk/lib/_internal/pub_generated/test/dart2js/source_maps_include_core_libs_test.dart
deleted file mode 100644
index 6e0647f669df45663c38b47431850d20d12121bd..0000000000000000000000000000000000000000
--- a/sdk/lib/_internal/pub_generated/test/dart2js/source_maps_include_core_libs_test.dart
+++ /dev/null
@@ -1,72 +0,0 @@
-// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS d.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 'package:scheduled_test/scheduled_test.dart';
-
-import '../descriptor.dart' as d;
-import '../test_pub.dart';
-
-main() {
-  initConfig();
-
-  // This test is a bit shaky. Since dart2js is free to inline things, it's
-  // not precise as to which source libraries will actually be referenced in
-  // the source map. But this tries to use a type in the core library
-  // (StringBuffer) and validate that its source ends up in the source map.
-  integration("Dart core libraries are available to source maps", () {
-    d.dir(
-        appPath,
-        [
-            d.appPubspec(),
-            d.dir(
-                "web",
-                [
-                    d.file("main.dart", "main() => new StringBuffer().writeAll(['s']);"),
-                    d.dir(
-                        "sub",
-                        [
-                            d.file(
-                                "main.dart",
-                                "main() => new StringBuffer().writeAll(['s']);")])])]).create();
-
-    schedulePub(
-        args: ["build", "--mode", "debug"],
-        output: new RegExp(r'Built \d+ files to "build".'),
-        exitCode: 0);
-
-    d.dir(
-        appPath,
-        [
-            d.dir(
-                "build",
-                [
-                    d.dir(
-                        "web",
-                        [
-                            d.matcherFile(
-                                "main.dart.js.map",
-                                contains(r"packages/$sdk/lib/core/string_buffer.dart")),
-                            d.dir(
-                                "sub",
-                                [
-                                    d.matcherFile(
-                                        "main.dart.js.map",
-                                        contains(r"../packages/$sdk/lib/core/string_buffer.dart"))]),
-                            d.dir(
-                                "packages",
-                                [
-                                    d.dir(
-                                        r"$sdk",
-                                        [
-                                            d.dir(
-                                                "lib",
-                                                [
-                                                    d.dir(
-                                                        r"core",
-                                                        [
-                                                            d.matcherFile(
-                                                                "string_buffer.dart",
-                                                                contains("class StringBuffer"))])])])])])])]).validate();
-  });
-}