and adjust the path in the Makefile for the upgrade_checks target.
These checks are really feature upgrade checks that should be fast
and just find out whether we need to build a new make before
proceeding with other targets like buildworld. This makes the
place free for a real regression test suite in the old place.
and for proper behaviour of some sed functions given a nil pattern space,
as fixed in PR 34813.
The test for G was based on the test in the PR. The nil pattern space test
is slightly different as we need to get *some* output, as the core dump will
also produce no output (old behaviour) and turn up falsely that the utility
is working fine.