correct function arg order

[graingert]

When simple static analysis can trivially work out that the argument order is obviously wrong:

// good
_.map(x => x.y, vals);

// bad
_.map(vals, x => x.y);

// bad
_.map([a, b, c], eg);

// ok - unnecessary wrap should catch it though.
function foo(vals, f) {
  return _.map(vals, f);
}

// ok - undefined var should catch it.
_.map(vals, ff);

// ok - nothing you can do about this, you're 'pwnd'.
const fff = getFn();
_.map(vals, fff);

// bad
function ffff(x) {
  return x.y;
}

_.map(vals, ffff);