Enable issue tests that appear to be incorrectly named.

tests/language/issue_1751477.dart

-// Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-import 'issue_1751477_lib1.dart' deferred as lib1;
-import 'issue_1751477_lib2.dart' deferred as lib2;
-import 'issue_1751477_lib3.dart' deferred as lib3;
-import 'issue_1751477_lib4.dart' deferred as lib4;
-import 'issue_1751477_lib5.dart' deferred as lib5;
-import 'issue_1751477_lib6.dart' deferred as lib6;
-import 'issue_1751477_lib7.dart' deferred as lib7;
-import 'issue_1751477_lib8.dart' deferred as lib8;
-import 'issue_1751477_lib9.dart' deferred as lib9;
-
-main() {
-  lib1.loadLibrary().then((_) {
-    lib2.loadLibrary().then((_) {
-      lib3.loadLibrary().then((_) {
-        lib4.loadLibrary().then((_) {
-          lib5.loadLibrary().then((_) {
-            lib6.loadLibrary().then((_) {
-              lib7.loadLibrary().then((_) {
-                lib8.loadLibrary().then((_) {
-                  lib9.loadLibrary().then((_) {
-                  });
-                });
-              });
-            });
-          });
-        });
-      });
-    });
-  });
-}