ugly compiler note for %COERCE-CALLABLE-TO-FUN

[Nikodemus Siivola]

   (defun foo (x)
     (declare (optimize speed))
     (funcall x))

gives

  ; in: DEFUN FOO
  ; (FUNCALL X)
  ; --> SB-C::%FUNCALL THE
  ; ==>
  ; (SB-KERNEL:%COERCE-CALLABLE-TO-FUN X)
  ;
  ; note: unable to
  ; optimize
  ; because:
  ; optimize away possible call to FDEFINITION at runtime

where something along the lines of

  ; in: DEFUN FOO
  ; (FUNCALL X)
  ;
  ; note: unable to
  ; optimize away possible call to FDEFINITION at runtime
  ; because:
  ; X is not known to be a FUNCTION

would be more desirable.

[Douglas Katzman (dougk)]

The efficiency note seems fine to me:
"; note: unable to optimize away possible call to FDEFINITION at runtime because: not known to be a function"