Fix subtle bug when checking liveness of module values.

Fix subtle bug when checking liveness of module values.

We can't simply look up the Lisp object in the global reference table
because an invalid local and a valid global reference might refer to
the same object.  Instead, we have to test the address of the global
reference against the stored references.

* src/emacs-module.c (module_global_reference_p): New helper function.
(value_to_lisp): Use it.

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

* test/src/emacs-module-tests.el
(module--test-assertions--load-non-live-object-with-global-copy):
New unit test.