* lib/wctype_.h [HAVE_WINT_T]: Include <stddef.h> before <wchar.h>, to work around BSDI bug in BSD/OS 4.0.1. * m4/wcwidth.m4 (gl_FUNC_WCWIDTH): Likewise. * m4/wint_t.m4 (gt_TYPE_WINT_T): Likewise. Reported by Chris McGuire.