Fix panic in 'remove semicolon' when types are not local
It's not possible to check if removing a semicolon fixes the type error
when checking match arms and one or both of the last arm's and the
current arm's return types are imported "opaque" types. In these cases
we don't generate a "consider removing semicolon" suggestions.
Fixes#81839
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I'm not sure how to add a test for this. I think the test would need at least two crates. Do we have any existing tests that do this so that I can take a look?
39af025741