binutils: Require GNU tail for 'objdump -Wi' test

testsuite/binutils-all/objdump.exp has

set got [remote_exec host "tail -n +4 tmpdir/objdump.out" "" "/dev/null" "tmpdir/objdump.tail"]

But the default Solaris tail doesn't support "tail -n +4".  Add
ACX_PROG_GNU_TAIL to use GNU tail for 'objdump -Wi' test.

Tested on Linux and Solaris.

binutils/

	PR binutils/33396
	* Makefile.am (check-DEJAGNU): Also export TAIL.
	* Makefile.in: Regenerated.
	* aclocal.m4: Likewise.
	* configure: Likewise.
	* configure.ac: Add ACX_PROG_GNU_TAIL.
	* testsuite/binutils-all/objdump.exp: Require GNU tail for
	'objdump -Wi' test and replace tail with $env(TAIL).

config/

	PR binutils/33396
	* acx.m4 (ACX_PROG_GNU_TAIL): New.

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Collin Funk <collin.funk1@gmail.com>