[CM] bug with #'signum in run

[Anders Vinjar]

(I have only checked this with clm-3 & cmucl)

(signum samp) returns 0.0 for values between -1.0 and 1.0 inside
run-loop


(definstrument test (amp)
  (run
   (loop for i from 0 to 10 do
     (clm-print "~A" (signum (* amp (- (random 1.0) 1.0)))))))

(with-sound () (test 1.0))

* 0,0,0,0,0,0,0,0,0,0,0,
"test.snd"

(with-sound () (test 2.0))

* 0,-1,0,-1,-1,-1,0,0,-1,0,-1,
"test.snd"
*