Rollup merge of rust-lang#55081 - sinkuu:dedup_test, r=Manishearth

Deduplicate tests

* [`ui/lifetimes/lifetime-errors/ex3-both-anon-regions-both-are-structs-4`](https://github.com/rust-lang/rust/blob/0c665e20db6c61de8f741bca3ca7660e679885c0/src/test/ui/lifetimes/lifetime-errors/ex3-both-anon-regions-both-are-structs-4.rs)
and [`ex3-both-anon-regions-both-are-structs-3`](https://github.com/rust-lang/rust/blob/0c665e20db6c61de8f741bca3ca7660e679885c0/src/test/ui/lifetimes/lifetime-errors/ex3-both-anon-regions-both-are-structs-3.rs)
* [`ui/lint/lint-group-style`](https://github.com/rust-lang/rust/blob/0c665e20db6c61de8f741bca3ca7660e679885c0/src/test/ui/lint/lint-group-style.rs) and [`lint-group-nonstandard-style`](https://github.com/rust-lang/rust/blob/0c665e20db6c61de8f741bca3ca7660e679885c0/src/test/ui/lint/lint-group-nonstandard-style.rs)

Author: Manishearth