Fix native comp prediction on null functionp tested objects

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.

(cherry picked from commit 8cc67dbcec0753c5579e63bf82bfe247debe222c)