Incorrect emit of defining class expression with static property inside loop

[yuit]

As @jeffreymorlan points out in the PR #8551, below code is emited incorrectly.

Compiler options: --target es5, --target es6

const arr: {y(): number}[] = [];
for (let i = 0; i < 3; i++) {
    arr.push(class C {
        static x = i;
        static y = () => C.x * 2;
    });
}
arr.forEach(C => console.log(C.y()));