Reported by Tom G. Christensen <tgc@jupiterrise.com> in
<https://lists.gnu.org/archive/html/bug-gnulib/2020-11/msg00062.html>.
* modules/getumask-tests (Makefile.am): Link test-getumask with
$(LIBINTL).
* modules/stack-tests (Makefile.am): Link test-stack with $(LIBINTL).
* modules/supersede-tests (Makefile.am): Link test-supersede with
$(LIBINTL).
* modules/unicodeio-tests (Makefile.am): Link test-unicodeio with
$(LIBINTL).
* MODULES.html.sh: Add entry for the stack module.
* modules/stack: New file.
* modules/stack-tests: New file.
* lib/stack.h: New file.
* tests/test-stack.c: New file.