Problems reported by Bruno Haible in:
http://lists.gnu.org/archive/html/bug-gnulib/2017-03/msg00078.html
* lib/stdalign.in.h (_Alignas):
* m4/stdalign.m4 (gl_STDALIGN_H):
Use octal, not decimal, for __HP_cc version. Perhaps HP formerly
used octal (as that is how they document it), but it is decimal in
practice now and the ancient implementations no longer matter.
* tests/test-stdalign.c (main) [__HP_cc && __ia64]: Skip test.