Support globs in $include and $exclude.

sdk/lib/_internal/pub/test/transformer/exclusion/include_asset_prefix_test.dart

Index: sdk/lib/_internal/pub/test/transformer/exclusion/include_asset_prefix_test.dart
diff --git a/sdk/lib/_internal/pub/test/transformer/exclusion/exclude_asset_string_test.dart b/sdk/lib/_internal/pub/test/transformer/exclusion/include_asset_prefix_test.dart
similarity index 81%
copy from sdk/lib/_internal/pub/test/transformer/exclusion/exclude_asset_string_test.dart
copy to sdk/lib/_internal/pub/test/transformer/exclusion/include_asset_prefix_test.dart
index 81e41635cf7b637af26b536dd1c0d90a2acde6b3..6434b64dee4960fdaede00f6306756fc81068f09 100644
--- a/sdk/lib/_internal/pub/test/transformer/exclusion/exclude_asset_string_test.dart
+++ b/sdk/lib/_internal/pub/test/transformer/exclusion/include_asset_prefix_test.dart
@@ -11,14 +11,14 @@ import '../../serve/utils.dart';
 main() {
   initConfig();
   withBarbackVersions("any", () {
-    integration("allows a single string as the asset to exclude", () {
+    integration("allows a directory prefix to include", () {
       d.dir(appPath, [
         d.pubspec({
           "name": "myapp",
           "transformers": [
             {
               "myapp/src/transformer": {
-                "\$exclude": "web/foo.txt"
+                "\$include": "web/sub"
               }
             }
           ]
@@ -31,6 +31,9 @@ main() {
           d.file("bar.txt", "bar"),
           d.dir("sub", [
             d.file("foo.txt", "foo"),
+          ]),
+          d.dir("subbub", [
+            d.file("foo.txt", "foo"),
           ])
         ])
       ]).create();
@@ -39,8 +42,9 @@ main() {
 
       pubServe();
       requestShould404("foo.out");
+      requestShould404("bar.out");
       requestShouldSucceed("sub/foo.out", "foo.out");
-      requestShouldSucceed("bar.out", "bar.out");
+      requestShould404("subbub/foo.out");
       endPubServe();
     });
   });