Fix for expected/found not showing in old school mode

[sophiajt]

This fixes#33366 by turning on the expected/found notes for old school mode. It does so by plumbing through access to check_old_skool()

cc @birkenfeld (builds on #33367)

[rust-highfive]

r? @nrc

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[nikomatsakis]

so, what I was trying to say before was that if we wanted to have something more like the old output, we could remove the modification below and instead change this line to:

let message = if check_old_skool() {
format("{} ({})", trace.origin, terr)
} else {
format("{}", trace.origin)
};
let mut err = struct_span_err!(..., "{}", message);

But I guess I'm ok either way.

[nikomatsakis]

@bors r+

[bors]

📌 Commit 430ee0a has been approved by nikomatsakis

[bors]

☔ The latest upstream changes (presumably #33619) made this pull request unmergeable. Please resolve the merge conflicts.