cmake: make it easier to diagnose regressions in CTest runs

When a test script fails in Git's test suite, the usual course of action
is to re-run it using options to increase the verbosity of the output,
e.g. `-v` and `-x`.

Like in Git's CI runs, when running the tests in Visual Studio via the
CTest route, it is cumbersome or at least requires a very unintuitive
approach to pass options to the test scripts: the CMakeLists.txt file
would have to be modified, passing the desired options to _all_ test
scripts, and then the CMake Cache would have to be reconfigured before
running the test in question individually. Unintuitive at best, and
opposite to the niceties IDE users expect.

So let's just pass those options by default: This will not clutter any
output window but the log that is written to a log file will have
information necessary to figure out test failures.

While at it, also imitate what the Windows jobs in Git's CI runs do to
accelerate running the test scripts: pass the `--no-bin-wrappers` and
`--no-chain-lint` options.

This makes the test runs noticeably faster because the `bin-wrappers/`
scripts as well as the `chain-lint` code make heavy use of POSIX shell
scripting, which is really, really slow on Windows due to the need to
emulate POSIX behavior via the MSYS2 runtime. In a test by Eric
Sunshine, it added two minutes (!) just to perform the chain-lint task.

The idea of adding a CMake config option (á la `GIT_TEST_OPTS`) was
considered during the development of this patch, but then dropped: such
a setting is global, across _all_ tests, where e.g. `--run=...` would
not make sense. Users wishing to override these new defaults are better
advised running the test script manually, in a Git Bash, with full
control over the command line.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

contrib/buildsystems/CMakeLists.txt

@@ -1088,7 +1088,7 @@ file(GLOB test_scipts "${CMAKE_SOURCE_DIR}/t/t[0-9]*.sh")
 #test
 foreach(tsh ${test_scipts})
 	add_test(NAME ${tsh}
-		COMMAND ${SH_EXE} ${tsh}
+		COMMAND ${SH_EXE} ${tsh} --no-bin-wrappers --no-chain-lint -vx
 		WORKING_DIRECTORY ${CMAKE_SOURCE_DIR}/t)
 endforeach()