Support `rustc_skip_array_during_method_dispatch`

[flodiebold]

Likely part of the 2021 edition, so this is just so we don't forget about this: rust-lang/rust#84147

(Actually if we don't support this type inference will be wrong for 2015 and 2018.)

[m-ou-se]

Note that this is already part of Rust 1.53.0 (to be released June 17th) and active in the current editions.