implement PartialEq<Vec<U>> for [T; N] and &[T; N]

[Qelxiros]

Closes #149017

@Centril you're mentioned in the FIXME; do you have thoughts on this?

[rustbot]

r? @JonathanBrouwer

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[reddevilmidzy]

How about adding the test mentioned in the issue?

fn main() {
    let x = vec![1];
    let y = [1];
    let _ = x == y;
    let _ = y == x;
}

[JonathanBrouwer]

r? libs