Store the async-await compiled pub code directly in the repo.

sdk/lib/_internal/pub_generated/test/global/activate/snapshots_hosted_executables_test.dart

+import 'package:scheduled_test/scheduled_test.dart';
+import '../../descriptor.dart' as d;
+import '../../test_pub.dart';
+main() {
+  initConfig();
+  integration('snapshots the executables for a hosted package', () {
+    servePackages((builder) {
+      builder.serve(
+          "foo",
+          "1.0.0",
+          contents: [
+              d.dir(
+                  'bin',
+                  [
+                      d.file("hello.dart", "void main() => print('hello!');"),
+                      d.file("goodbye.dart", "void main() => print('goodbye!');"),
+                      d.file("shell.sh", "echo shell"),
+                      d.dir("subdir", [d.file("sub.dart", "void main() => print('sub!');")])])]);
+    });
+    schedulePub(
+        args: ["global", "activate", "foo"],
+        output: allOf(
+            [contains('Precompiled foo:hello.'), contains("Precompiled foo:goodbye.")]));
+    d.dir(
+        cachePath,
+        [
+            d.dir(
+                'global_packages',
+                [
+                    d.dir(
+                        'foo',
+                        [
+                            d.matcherFile('pubspec.lock', contains('1.0.0')),
+                            d.dir(
+                                'bin',
+                                [
+                                    d.matcherFile('hello.dart.snapshot', contains('hello!')),
+                                    d.matcherFile('goodbye.dart.snapshot', contains('goodbye!')),
+                                    d.nothing('shell.sh.snapshot'),
+                                    d.nothing('subdir')])])])]).validate();
+  });
+}