wctype: Rely on module iswpunct.
* m4/wctype.m4 (gl_FUNC_WCTYPE): Also test whether the "punct" class
works.
* modules/wctype (Depends-on): Add iswpunct.
* tests/test-iswctype.c (main): Add more tests of the "punct" class.
* doc/posix-functions/wctype.texi: Mention the Android problem.
iswctype: Add tests.
* tests/test-iswctype.c: New file, based on
tests/test-c32_apply_type_test.c.
* tests/test-c32_apply_type_test.c (main): Update accordingly.
* modules/iswctype-tests: New file.