This incorporates:
2014-06-02 acl: apply pure attribute to two functions
2014-06-01 gnulib-common.m4: add _GL_UNUSED_LABEL
2014-05-31 dup2, fcntl, fcntl-h: port to AIX 7.1
2014-05-30 ftoastr: work around compiler bug in IBM xlc 12.1
* lib/acl-internal.h, lib/fcntl.in.h, lib/ftoastr.h:
* m4/dup2.m4, m4/fcntl.m4, m4/gnulib-common.m4:
Update from gnulib.