Compilation fails in SB-C::DELETE-BLOCK with "The value NIL is not of type SB-C::CTRAN"

[Ilya Perminov]

SB-C::DELETE-BLOCK signals type error "The value NIL is not of type SB-C::CTRAN" during compilation of the following code:
(declaim (inline call))
(defun call (function)
  (flet ((func1 ()
           (unwind-protect
                (funcall function)
             nil)))
    (declare (inline func1))
    (if function
        (func1)
        (func1))))

(defun test-call ()
  (flet ((func () 1))
    (call #'func))
  (flet ((func () 1))
    (call #'func))
  )

SBCL 1.2.7, Linux x86_64

[Stas Boukarev (stassats)]

In 04dbaae75369e271358e33f77d26cbffc32acc24