* tests/test-mbstoc32s.c: New file, based on tests/test-mbsrtoc32s.c.
* tests/test-mbstoc32s-1.sh: New file, based on
tests/test-mbsrtoc32s-1.sh.
* tests/test-mbstoc32s-2.sh: New file, based on
tests/test-mbsrtoc32s-2.sh.
* tests/test-mbstoc32s-3.sh: New file, based on
tests/test-mbsrtoc32s-3.sh.
* tests/test-mbstoc32s-4.sh: New file, based on
tests/test-mbsrtoc32s-4.sh.
* modules/mbstoc32s-tests: New file, based on modules/mbsrtoc32s-tests.