Don't `return std::move(local)`

Reason

Returning a local variable implicitly moves it anyway. An explicit std::move is always a pessimization, because it prevents Return Value Optimization (RVO), which can eliminate the move completely.

Example, bad

S bad()
{
  S result;
  return std::move(result);
}

Example, good

S good()
{
  S result;
  // Named RVO: move elision at best, move construction at worst
  return result;
}

Enforcement

This should be enforced by tooling by checking the return expression.