Hide self-referential symlinks behind a flag in pub.

utils/tests/pub/pub_update_test.dart

Index: utils/tests/pub/pub_update_test.dart
diff --git a/utils/tests/pub/pub_update_test.dart b/utils/tests/pub/pub_update_test.dart
index 179d903f479d6b9da25c47400b6b0bee3fa231f8..27b2e70ec95abc902c16734c275f8a4989abce89 100644
--- a/utils/tests/pub/pub_update_test.dart
+++ b/utils/tests/pub/pub_update_test.dart
@@ -33,6 +33,8 @@ main() {
     });
   });
 
+  // TODO(rnystrom): Re-enable this when #4820 is fixed.
+  /*
   test('creates a self-referential symlink', () {
     // The symlink should use the name in the pubspec, not the name of the
     // directory.
@@ -49,4 +51,5 @@ main() {
 
     run();
   });
+  */
 }