Bug: Excess variable introduced in destructured for ... from loop

[STRd6]

Input Code

for {x} from y
  x

Expected Behavior

var x;
for ({x} of y) {
  x;
}

Current Behavior

var x, z;

for (z of y) {
  ({x} = z);
  x;
}

Possible Solution

Extra variable z shouldn't be introduced.

• CoffeeScript version: 2.7.0