Unreachable statements in Complex.abs()

This return statement in Complex.abs() is unreachable:

if (FastMath.abs(real) < FastMath.abs(imaginary)) {
  if (imaginary == 0.0) {
    return FastMath.abs(real);
  }

If imaginary == 0, then there's no way that the preceding condition would be true. There are two similar inner 'if' statements that were accidentally switched. Returned values are still correct, but performance suffers.

The attached patch switches these back. Note that we're still protected from dividing by zero.