Add missing copyright on test cases.

pkg/front_end/testcases/void-methods.dart.outline.expect

Index: pkg/front_end/testcases/void-methods.dart.outline.expect
diff --git a/pkg/front_end/testcases/void-methods.dart.outline.expect b/pkg/front_end/testcases/void-methods.dart.outline.expect
deleted file mode 100644
index 6b4a5049d468091f2f59b0c90532811838ea9bd8..0000000000000000000000000000000000000000
--- a/pkg/front_end/testcases/void-methods.dart.outline.expect
+++ /dev/null
@@ -1,17 +0,0 @@
-library;
-import self as self;
-import "dart:core" as core;
-
-class Foo extends core::Object {
-  field core::List<dynamic> list;
-  default constructor •() → void
-    ;
-  set first(dynamic x) → dynamic
-    ;
-  operator []=(dynamic x, dynamic y) → dynamic
-    ;
-  method clear() → void
-    ;
-}
-static method main() → dynamic
-  ;