stdalign: restore previous behavior for HP-UX IA64 See Bruno Haible's email in: http://lists.gnu.org/archive/html/bug-gnulib/2017-03/msg00066.html which cites p 150 of a manual saying that 'aligned' works on Itanium. * lib/stdalign.in.h (_Alignas): Assume the '061200' applies to Itanium, not to PA-RISC. * m4/stdalign.m4 (gl_STDALIGN_H): Adjust to match stdalign.in.h.