Warn on loop-match-break, replace with while-let

[Zarathustra30]

Loop-match-break constructs like this snippet stolen from the benchmarks game:

loop {
    let bi = match bodies.next() {
        Some(bi) => bi,
        None => break
    };
    ...
}

can be replaced with a simple while let:

while let Some(bi) = bodies.next() {
    ...
}

Loop-match-breaks don't do anything bad, but they decrease readability and make control flow more confusing. Are there any cases where while-let would not suffice?

[llogiq]

If there is something unrelated between the loop and the match.

Apart from that we may also want to detect the same thing with if-let instead of match.