Create binstubs for executables when activating a package.

sdk/lib/_internal/pub/lib/src/validator/name.dart

Index: sdk/lib/_internal/pub/lib/src/validator/name.dart
diff --git a/sdk/lib/_internal/pub/lib/src/validator/name.dart b/sdk/lib/_internal/pub/lib/src/validator/name.dart
index 14da9120035bc4427d42f7e0f3c2196e95870f37..585a3df877a5fb31868515c3f7edb9ae6acc80d0 100644
--- a/sdk/lib/_internal/pub/lib/src/validator/name.dart
+++ b/sdk/lib/_internal/pub/lib/src/validator/name.dart
@@ -52,8 +52,7 @@ class NameValidator extends Validator {
   /// to the package's root directory.
   List<String> get _libraries {
     var libDir = path.join(entrypoint.root.dir, "lib");
-    if (!dirExists(libDir)) return [];
-    return entrypoint.root.listFiles(beneath: libDir)
+    return entrypoint.root.listFiles(beneath: "lib")
         .map((file) => path.relative(file, from: path.dirname(libDir)))
         .where((file) => !path.split(file).contains("src") &&
                          path.extension(file) == '.dart')