function foo(o) {
    o.x = 1;
    o.y = 2;
    o.a = 3;
    o.b = 4;
    o.c = 5;
    o.d = 6;
    o.e = 7;
    o.f = 8;
    o.g = 9;
    o.h = 10;
    o.i = 11;
}

function Foo() {
    foo(this);
}

var result = 0;

for (var i = 0; i < 100000; ++i) {
    foo({f:42});
    result += (new Foo()).x;
}

if (result != 100000)
    throw "Bad result: " + result;