Move kernel baseline tests to front_end.

pkg/front_end/test/fasta/rasta/issue_000053.dart.dartk.expect

-library;
-import self as self;
-import "dart:core" as core;
-
-class C extends core::Object {
-  constructor •() → self::C
-    : super core::Object::•();
-  operator ==(dynamic other) → dynamic
-    return throw "x";
-  method test() → dynamic {
-    super.{core::Object::==}(null);
-  }
-}
-static method main() → dynamic {
-  new self::C::•().test();
-}