Rollup merge of #89738 - eddyb:extern-crate-recursion, r=nagisa

Rollup merge of #89738 - eddyb:extern-crate-recursion, r=nagisa

ty::pretty: prevent infinite recursion for `extern crate` paths.

Fixes #55779, fixes #87932.

This fix is based on `@estebank's` idea in https://github.com/rust-lang/rust/issues/55779#issuecomment-614758510 - but instead of trying to get `try_print_visible_def_path_recur`'s cycle detection to work in this case, this PR "just" disables the "visible path" feature when printing the path to an `extern crate`, so that the old recursion chain of `try_print_visible_def_path -> print_def_path -> try_print_visible_def_path`, is now impossible.

Both tests have been confirmed to crash `rustc` because of a stack overflow, without the fix.