Make checking for liveness of global values more precise.

Make checking for liveness of global values more precise.

We can't just use a hash lookup because a global and a local reference
might refer to the same Lisp object.

* src/emacs-module.c (module_free_global_ref): More precise check for
global liveness.

* test/data/emacs-module/mod-test.c (Fmod_test_globref_invalid_free):
New test module function.
(emacs_module_init): Export it.

* test/src/emacs-module-tests.el
(module--test-assertions--globref-invalid-free): New unit test.