when matching ellipses, values are wrongly bound

Created by: jlongster

I think this is a bug:

macro foo {
    rule { $x $[...] $y } => {
        ($x + $y)
    }
}

foo 5 ... 6;

This produces:

% sjs -p t.sjs
 ( 5 + ... ) 6 ; 

It seems like it does match the ellipses, but it unexpectedly gets bound to $y for some reason, when it seems like it should be 6.