While working on #54528 (see https://github.com/rust-lang/rust/projects/10) I found a number of tests that assume borrows to be lexically scoped. These tests should be revised to not rely on that assumption. (see also https://github.com/rust-lang/rust/issues/52663#issuecomment-409028095 and https://github.com/rust-lang/rust/projects/10#column-3663841)