Auto merge of #135994 - 1c3t3a:rename-unsafe-ptr, r=oli-obk

Rename rustc_middle::Ty::is_unsafe_ptr to is_raw_ptr

The wording unsafe pointer is less common and not mentioned in a lot of places, instead this is usually called a "raw pointer". For the sake of uniformity, we rename this method.
This came up during the review of
rust-lang/rust#134424.

r? `@Noratrieb`

Author: bors