Rollup merge of #70413 - AminArria:match-pattern-incorrect-warning, r=Centril,Nadrieril,varkor

Fix incorrect pattern warning "unreachable pattern"

Fixes #70372

Added `is_under_guard` parameter to `_match::is_useful` and only add it to the matrix if `false`

Tested with:
```rust
#![feature(or_patterns)]
fn main() {
    match (3,42) {
        (a,_) | (_,a) if a > 10 => {println!("{}", a)}
        _ => ()
    }

    match Some((3,42)) {
        Some((a, _)) | Some((_, a)) if a > 10 => {println!("{}", a)}
        _ => ()

    }

    match Some((3,42)) {
        Some((a, _) | (_, a)) if a > 10 => {println!("{}", a)}
        _ => ()
    }
}
```

0 files changed, 0 insertions, 0 deletions