Fix Hurd glibc build with GCC 8.

Fix Hurd glibc build with GCC 8.

The build of glibc for Hurd has been failing with GCC mainline because
of the checks that aliases have the same type as the symbol aliased;
the Hurd dl-sysdep.c has a macro that defines aliases without using
the proper type.  When GCC 8 branches (soon), I intend to make it the
default version in build-many-glibcs.py, so these failures would mean
the default build-many-glibcs.py build fails for Hurd again.

This patch fixes the Hurd build with GCC 8 by changing the macro that
defines the problem aliases to use the correct type for them.  An
include of <not-errno.h> is needed to avoid this use of typeof
resulting in an error for __access_noerrno not being declared.

Tested compilation for i686-gnu with build-many-glibcs.py.

	* sysdeps/mach/hurd/dl-sysdep.c: Include <not-errno.h>.
	(check_no_hidden): Use type of original function when declaring
	alias.