Fix crash on mandatory parameters with initializers.

test/kernel/regression/mandatory_parameter_initializer.dart

Index: test/kernel/regression/mandatory_parameter_initializer.dart
diff --git a/test/kernel/regression/bad_interpolation.dart b/test/kernel/regression/mandatory_parameter_initializer.dart
similarity index 89%
copy from test/kernel/regression/bad_interpolation.dart
copy to test/kernel/regression/mandatory_parameter_initializer.dart
index 98fd62e1573d05bec4f9a0e0781b6159189b0a1a..60805fe059b853760ea5559d882345685ec17fee 100644
--- a/test/kernel/regression/bad_interpolation.dart
+++ b/test/kernel/regression/mandatory_parameter_initializer.dart
@@ -2,6 +2,5 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE.md file.
 
-main() {
-  print(" $x.);
+main(arguments = [x]) {
 }