t: drop "verbose" helper function

t: drop "verbose" helper function

We have a small helper function called "verbose", with the idea that you
can write:

  verbose foo

to get a message to stderr when the "foo" command fails, even if it does
not produce any output itself. This goes back to 8ad1652418 (t5304: use
helper to report failure of "test foo = bar", 2014-10-10). It does work,
but overall it has not been a big success for two reasons:

  1. Test writers have to remember to put it there (and the resulting
     test code is longer as a result).

  2. It doesn't handle the opposite case (we expect "foo" to fail, but
     it succeeds), leading to inconsistencies in tests (which you can
     see in many hunks of this patch, e.g. ones involving "has_cr").

Most importantly, we added a136f6d8ff (test-lib.sh: support -x option
for shell-tracing, 2014-10-10) at the same time, and it does roughly the
same thing. The output is not quite as succinct as "verbose", and you
have to watch out for stray shell-traces ending up in stderr. But it
solves both of the problems above, and has clearly become the preferred
tool.

Let's consider the "verbose" function a failed experiment and remove the
last few callers (which are all many years old, and have been dwindling
as we remove them from scripts we touch for other reasons). It will be
one less thing for new test writers to see and wonder if they should be
using themselves.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>