test-lib: make "-x" work with "--verbose-log"
The "-x" tracing option implies "--verbose". This is a
problem when running under a TAP harness like "prove", where
we need to use "--verbose-log" instead. Instead, let's
handle this the same way we do for --valgrind, including the
recent fix from
88c6e9d31c (test-lib: --valgrind should not
override --verbose-log, 2017-09-05). Namely, let's enable
--verbose only when we know there isn't a more specific
verbosity option indicated.
Note that we also have to tweak `want_trace` to turn it on
(previously we just lumped $verbose_log in with $verbose,
but now we don't necessarily auto-set the latter).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>