non-recursive-gnulib-prefix-hack: port coreutils 8.21 to HP NonStop * m4/non-recursive-gnulib-prefix-hack.m4 (gl_NON_RECURSIVE_GNULIB_PREFIX_HACK): Don't mess with ALLOCA. Problem reported for HP NonStop + coreutils 8.21 by Joachim Schmitz in <http://bugs.gnu.org/10305#237>.