Put "packages" directories in "benchmark".

sdk/lib/_internal/pub/test/validator/directory_test.dart

Index: sdk/lib/_internal/pub/test/validator/directory_test.dart
diff --git a/sdk/lib/_internal/pub/test/validator/directory_test.dart b/sdk/lib/_internal/pub/test/validator/directory_test.dart
index e3acfb4b2bf5992b82801dee275c6e50f52cd151..1b58b6994eef8956803dc44e64e278a2db9d6f2a 100644
--- a/sdk/lib/_internal/pub/test/validator/directory_test.dart
+++ b/sdk/lib/_internal/pub/test/validator/directory_test.dart
@@ -35,7 +35,10 @@ main() {
       'named', () {
     setUp(d.validPackage.create);
 
-    var names = ["tools", "tests", "docs", "examples", "sample", "samples"];
+    var names = [
+      "benchmarks", "docs", "examples", "sample", "samples", "tests", "tools"
+    ];
+
     for (var name in names) {
       integration('"$name"', () {
         d.dir(appPath, [d.dir(name)]).create();