Clean up inline assignments

[Kyuuhachi]

The following code

var r,i=(r=n(224736))&&r.__esModule?r:{default:r};

is unminified to

var r;
var i = (r = n(224736)) && r.__esModule ? r : {default: r};

It would be nice if it could be rewritten as

var r = n(224736);
var i = r && r.__esModule ? r : {default: r};

One would have to be careful that this doesn't affect evaluation order, but I've seen that pattern often enough that it would be nice to have it fixed. I've seen similar things with if statements, var bi; if((bi=foo())===null||bi===void 0){, too.