Add more test case to check if the false note related to sealed trait suppressed
Closesrust-lang/rust#143121
I started to fix the issue but I found that this one has already been addressed in this PR (https://github.com/rust-lang/rust/pull/143431). I added an additional test to prove the reported thing has been resolved just in case.
I think we can discard this pull request if there's no need to add such kind of tests👍🏻