* modules/getprogname-tests (Depends-on): Remove assert-h.
It was not needed, and in fact would cause build failure for
coreutils on some systems. Reported by Assaf Gordon in https:
//lists.gnu.org/archive/html/coreutils/2016-09/msg00016.html
* lib/getprogname.c (getprogname): Include "dirname.h" and use
last_component: more general than open coding it with hard-coded "/".
* lib/getprogname.h (getprogname): Prefer "char const *" consistently.
* modules/getprogname (Depends-on): Add dirname-lgpl.
(configure.ac): Check for __argv in <stdlib.h>.
* modules/getprogname-tests: New file.
* tests/test-getprogname.c: New file.
Suggested by Gisle Vanem in
https://lists.gnu.org/archive/html/bug-gnulib/2016-09/msg00014.html
