Allow pretty printing paths with `-Zself-profile-events=args`
`-Zself-profile-events=args` is pretty heavy and can pretty print a lot of stuff. Rather than hunting down specific cases where this happens, I'd just allow calling `trimmed_def_paths` in this mode.
Fixes: https://github.com/rust-lang/rust/issues/144457
r? `@RalfJung`