Rollup merge of #123311 - Jules-Bertholet:andpat-everywhere, r=Nadrieril

Match ergonomics: implement "`&`pat everywhere"

Implements the eat-two-layers (feature gate `and_pat_everywhere`, all editions) ~and the eat-one-layer (feature gate `and_eat_one_layer_2024`, edition 2024 only, takes priority on that edition when both feature gates are active)~ (EDIT: will be done in later PR) semantics.

cc #123076

r? ``@Nadrieril``

``@rustbot`` label A-patterns A-edition-2024