* arm/redboot-syscalls.c: Consistently supply _isatty if syscalls dir is used in newlib. * bfin/syscalls.c: Ditto. * cris/gensyscalls: Ditto. * fr30/syscalls.c: Ditto. * frv/isatty.c: Ditto. * iq2000/isatty.c: Ditto. * libnosys/isatty.c: Ditto. * m32r/isatty.c: Ditto. * mn10200/isatty.c: Ditto. * mn10300/isatty.c: Ditto. * xstormy16/isatty.c: New file with _isatty function.