improve out-of-bounds checking with GCC 10 attribute access [BZ #25219]

improve out-of-bounds checking with GCC 10 attribute access [BZ #25219]

Adds the access attribute newly introduced in GCC 10 to the subset of
function declarations that are already covered by _FORTIFY_SOURCE and
that don't have corresponding GCC built-in equivalents.

Reviewed-by: DJ Delorie <dj@redhat.com>