modifications to arguments object not respected by Function.prototype.apply

[Ben Newman]

Modifying |arguments| with [].splice is broken:

function argc() { return arguments.length }

function test() {
    [].splice.call(arguments, 0, 0, 1);
    return [
        arguments.length,
        argc.apply(null, arguments)
    ];
}

test() // [1, 0]
test(1) // [2, 1]
test(1,2) // [3, 2]
test(1,2,3) // [4, 3]

[Ben Newman]

This works now, hey!