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

sdk/lib/_internal/pub_generated/test/cache/repair/reinstalls_hosted_packages_test.dart

+library pub_tests;
+import '../../descriptor.dart' as d;
+import '../../test_pub.dart';
+main() {
+  initConfig();
+  integration('reinstalls previously cached hosted packages', () {
+    servePackages((builder) {
+      builder.serve("foo", "1.2.3");
+      builder.serve("foo", "1.2.4");
+      builder.serve("foo", "1.2.5");
+      builder.serve("bar", "1.2.3");
+      builder.serve("bar", "1.2.4");
+    });
+    d.dir(
+        cachePath,
+        [
+            d.dir(
+                'hosted',
+                [
+                    d.async(
+                        port.then(
+                            (p) =>
+                                d.dir(
+                                    'localhost%58$p',
+                                    [
+                                        d.dir("foo-1.2.3", [d.libPubspec("foo", "1.2.3"), d.file("broken.txt")]),
+                                        d.dir("foo-1.2.5", [d.libPubspec("foo", "1.2.5"), d.file("broken.txt")]),
+                                        d.dir(
+                                            "bar-1.2.4",
+                                            [d.libPubspec("bar", "1.2.4"), d.file("broken.txt")])])))])]).create();
+    schedulePub(args: ["cache", "repair"], output: '''
+          Downloading bar 1.2.4...
+          Downloading foo 1.2.3...
+          Downloading foo 1.2.5...
+          Reinstalled 3 packages.''');
+    d.hostedCache(
+        [
+            d.dir("bar-1.2.4", [d.nothing("broken.txt")]),
+            d.dir("foo-1.2.3", [d.nothing("broken.txt")]),
+            d.dir("foo-1.2.5", [d.nothing("broken.txt")])]).validate();
+  });
+}