anglep: inline radians->int16 operation

RADIANS->INT16 declares, that the argument is of the type ANGLE. Some
implementations when declared put check-type, and the type ANGLE is
declared as (SATISFIES ANGLEP). Then, ANGLEP called RADIANS->INT16
internally what lead to infinite recursion.

dependent.lisp

@@ -387,7 +387,9 @@
 
   (defun anglep (x)
     (and (typep x 'real)
-         (<= (* -360 64) (radians->int16 x) (* 360 64)))))
+         (<= (* -360 64)
+             (the int16 (round x #.(float (/ pi 180.0s0 64.0s0) 0.0s0)))
+             (* 360 64)))))
 
 
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