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

sdk/lib/_internal/pub_generated/test/global/run/recompiles_if_sdk_is_out_of_date_test.dart

+import 'package:scheduled_test/scheduled_stream.dart';
+import 'package:scheduled_test/scheduled_test.dart';
+import '../../descriptor.dart' as d;
+import '../../test_pub.dart';
+main() {
+  initConfig();
+  integration('recompiles a script if the SDK version is out-of-date', () {
+    servePackages((builder) {
+      builder.serve(
+          "foo",
+          "1.0.0",
+          contents: [
+              d.dir("bin", [d.file("script.dart", "main(args) => print('ok');")])]);
+    });
+    schedulePub(args: ["global", "activate", "foo"]);
+    d.dir(
+        cachePath,
+        [
+            d.dir(
+                'global_packages',
+                [
+                    d.dir(
+                        'foo',
+                        [d.dir('bin', [d.outOfDateSnapshot('script.dart.snapshot')])])])]).create();
+    var pub = pubRun(global: true, args: ["foo:script"]);
+    pub.stdout.expect("Precompiling executables...");
+    pub.stdout.expect(consumeThrough("ok"));
+    pub.shouldExit();
+    d.dir(
+        cachePath,
+        [
+            d.dir(
+                'global_packages',
+                [
+                    d.dir(
+                        'foo',
+                        [
+                            d.dir(
+                                'bin',
+                                [d.matcherFile('script.dart.snapshot', contains('ok'))])])])]).validate();
+  });
+}