It needs to find the xz executable from a different directory
and work without config.h.
(cherry picked from commit a805594ed0b4cbf7b81aa28ff46a8ab3c83c6876)
This tests some complicated interactions with the --suffix= option.
The suffix option must be used with --format=raw, but can optionally
be used to override the default .xz suffix.
This test also verifies some recent bugs have been correctly solved
and to hopefully avoid further regressions in the future.
