Fix native comp prediction on null functionp tested objects

* lisp/emacs-lisp/comp.el (comp-known-predicates)
(comp-known-predicates-h): Update.
(comp--pred-to-pos-cstr, comp--pred-to-neg-cstr): New functions.
(comp--add-cond-cstrs): Make use of them.

* test/src/comp-tests.el (comp-tests-type-spec-tests): Add a test.

1 files changed, 8 insertions, 1 deletions

diff --git a/test/src/comp-tests.el b/test/src/comp-tests.el
index fbcb6ca9560..b2fd2f68826 100644
--- a/test/src/comp-tests.el
+++ b/test/src/comp-tests.el
@@ -1496,7 +1496,14 @@ Return a list of results."
          (if (comp-foo-p x)
              x
            (error "")))
-       'comp-foo)))
+       'comp-foo)
+
+      ;; 80
+      ((defun comp-tests-ret-type-spec-f (x)
+         (if (functionp x)
+             (error "")
+           x))
+       '(not function))))
 
   (defun comp-tests-define-type-spec-test (number x)
     `(comp-deftest ,(intern (format "ret-type-spec-%d" number)) ()