Move kernel baseline tests to front_end.

pkg/front_end/test/fasta/rasta/native_is_illegal.dart.direct.expect

-library;
-import self as self;
-import "dart:core" as core;
-
-class Bar extends core::Object {
-  get x() → self::Bar
-    return "Bar_get_x";
-  set x(self::Bar value) → dynamic
-    return "Bar_set_x";
-  method f() → dynamic
-    return "Bar_f";
-  static factory •() → self::Bar
-    return "Bar_constructor";
-}
-static method foo() → dynamic
-  invalid-statement;