localename: control langinfo.h inclusion This header is only used to work around buggy behavior in old versions of glibc, so do not include it all the time. Otherwise we get build failures on systems that do not provide langinfo.h. * lib/localename.c: Wrap langinfo.h include with same ifdefs used in the source later on. The patch was originally submitted to gettext as: https://lists.gnu.org/archive/html/bug-gettext/2015-10/msg00011.html