Allow DirectoryDescriptor.load to load a file next to a directory.

pkg/scheduled_test/test/descriptor/file_test.dart

Index: pkg/scheduled_test/test/descriptor/file_test.dart
diff --git a/pkg/scheduled_test/test/descriptor/file_test.dart b/pkg/scheduled_test/test/descriptor/file_test.dart
index 958f4316115703d3dd28f5fa45dc1514c323ec9d..03573b7194c14319be134c4521e48133e8b37550 100644
--- a/pkg/scheduled_test/test/descriptor/file_test.dart
+++ b/pkg/scheduled_test/test/descriptor/file_test.dart
@@ -114,14 +114,6 @@ void main() {
     });
   });
 
-  expectTestsPass("file().load() throws an error", () {
-    test('test', () {
-      expect(d.file('name.txt', 'contents').load('path').toList(),
-          throwsA(equals("Can't load 'path' from within 'name.txt': not a "
-                         "directory.")));
-    });
-  });
-
   expectTestsPass("file().describe() returns the filename", () {
     test('test', () {
       expect(d.file('name.txt', 'contents').describe(), equals('name.txt'));