Some Wine tests run code compiled from another C file, resulting in
traces and errors that look like they come from a different test.
subtest() allows such tests to declare their subtests so they are
recognized by scripts parsing the results such as the TestBot and
WineTest website.
Signed-off-by: Francois Gouget <fgouget@codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>