Move `analyzer_cli` into the SDK.

pkg/analyzer_cli/test/data/no_packages_file/sdk_ext_user.dart

Index: pkg/analyzer_cli/test/data/no_packages_file/sdk_ext_user.dart
diff --git a/tests/language/issue_23914_test.dart b/pkg/analyzer_cli/test/data/no_packages_file/sdk_ext_user.dart
similarity index 69%
copy from tests/language/issue_23914_test.dart
copy to pkg/analyzer_cli/test/data/no_packages_file/sdk_ext_user.dart
index 072f912b74cff3b0bbde89667b3ba30ea84ac71d..b346f7f1ed19a53ff94321f5a12737f3decde69f 100644
--- a/tests/language/issue_23914_test.dart
+++ b/pkg/analyzer_cli/test/data/no_packages_file/sdk_ext_user.dart
@@ -2,8 +2,9 @@
 // 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 'dart:collection';
+import 'dart:foo';
 
 main() {
-  var a = new List.unmodifiable(new LinkedList());
+  // import of 'dart:foo' should resolve to a file which defines bar().
+  bar();
 }