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

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

+import 'package:scheduled_test/scheduled_test.dart';
+import '../../descriptor.dart' as d;
+import '../../test_pub.dart';
+main() {
+  initConfig();
+  integration('uses the 1.6-style lockfile if necessary', () {
+    servePackages((builder) {
+      builder.serve("bar", "1.0.0");
+      builder.serve("foo", "1.0.0", deps: {
+        "bar": "any"
+      }, contents: [d.dir("bin", [d.file("script.dart", """
+              import 'package:bar/bar.dart' as bar;
+
+              main(args) => print(bar.main());""")])]);
+    });
+    schedulePub(args: ["cache", "add", "foo"]);
+    schedulePub(args: ["cache", "add", "bar"]);
+    d.dir(cachePath, [d.dir('global_packages', [d.file('foo.lock', '''
+packages:
+  foo:
+    description: foo
+    source: hosted
+    version: "1.0.0"
+  bar:
+    description: bar
+    source: hosted
+    version: "1.0.0"''')])]).create();
+    var pub = pubRun(global: true, args: ["foo:script"]);
+    pub.stdout.expect("bar 1.0.0");
+    pub.shouldExit();
+    d.dir(
+        cachePath,
+        [
+            d.dir(
+                'global_packages',
+                [
+                    d.nothing('foo.lock'),
+                    d.dir('foo', [d.matcherFile('pubspec.lock', contains('1.0.0'))])])]).validate();
+  });
+}