Segfault from incorrect capture

[brson]

I've hit this several times recently.

use core::pipes::*;

fn main() {
    let (po, ch) = stream();
    let ch = SharedChan(ch);

    for 100.times {
        do task::spawn {
            // ch should not be copyable
            ch.send(());
        }
    }
}

[nikomatsakis]

this is fixed on my branch

[nikomatsakis]

This no longer compiles.