Reassigning exported variable using a loop does not update symbol dependencies

Input:
```ts
let bar = '';
export { bar };
for (bar of ['a']) {}
```

Current Result:
```lua
local bar = ""
____exports.bar = bar
for ____, ____value in ipairs({"a"}) do
    bar = ____value
end
```

Expected Result:
```lua
local bar = ""
____exports.bar = bar
for ____, ____value in ipairs({"a"}) do
    bar = ____value
    ____exports.bar = bar
end
```