CLI support for embedders (#25380).

pkg/analyzer_cli/test/data/embedder_client/embedder_yaml_user.dart

Index: pkg/analyzer_cli/test/data/embedder_client/embedder_yaml_user.dart
diff --git a/tests/language/export_not_shadowed_by_prefix_helper2.dart b/pkg/analyzer_cli/test/data/embedder_client/embedder_yaml_user.dart
similarity index 61%
copy from tests/language/export_not_shadowed_by_prefix_helper2.dart
copy to pkg/analyzer_cli/test/data/embedder_client/embedder_yaml_user.dart
index ae2dca5fcf0a4842b29e20d7652b35b6bfd65cfc..2d88a2adebdfa58a10363e94f0250ef66aa8b6b6 100644
--- a/tests/language/export_not_shadowed_by_prefix_helper2.dart
+++ b/pkg/analyzer_cli/test/data/embedder_client/embedder_yaml_user.dart
@@ -2,8 +2,8 @@
 // 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.
 
-void f() {
-  f_called = true;
-}
+import 'dart:bear'; // Defined in package_with_embedder_yaml/lib/_embedder.yaml
 
-bool f_called = false;
+main() {
+  print(new Bear()); // Defined in 'dart:bear'
+}