Auto merge of #78553 - Nadrieril:fix-78549, r=varkor

Fix #78549

Before #78430, this worked because `specialize_constructor` didn't actually care too much which constructor was passed to it unless needed. That PR however handles `&str` as a special case, and I did not anticipate patterns for the `&str` type other than string literals.
I am not very confident there are not other similar oversights left, but hopefully only `&str` was different enough to break my assumptions.

Fixes https://github.com/rust-lang/rust/issues/78549

diff --cc compiler/rustc_mir_build/src/thir/pattern/_match.rs
Simple merge