Unneeded code in complex-acos
Describe the bug
complex-acos has this code:
(if (and (realp z) (> z 1)) ;; acos is continuous in quadrant IV in this case. (complex-acos (complex z -0f0))
AFAICT, this isn't actually needed. If you use eliminate this test and evaluate
(acos 2) and
(acos #c(2 -0.0), the results are the same:
I'm pretty sure Kahan's algorithm is correct, without having this extra test.