Don't use the angle mode, use the angle units included
in the expression instead (Bug#23889).
* lisp/calc/calc-alg.el (calc-input-angle-units): New defun.
(math-simplify): Use it.
* lisp/calc/calc-forms.el (math-to-hms, math-from-hms):
Don't use calc-angle-mode if math-simplifying-units is non-nil.
* lisp/calc/calc-math.el (calcFunc-nroot, math-from-radians)
(math-to-radians-2, math-from-radians-2): Don't convert angle
to radians if math-simplifying-units is non-nil.
* test/lisp/calc/calc-tests.el (test-calc-23889): Add test.
c48e539226