[Bug 39512] Make it possible to run multiple tests in a single task

https://bugs.winehq.org/show_bug.cgi?id=39512

--- Comment #1 from François Gouget  ---
This would also allow fixing the dependency issues (see bug 31789):
 * Do a global rebuild, relying on Wine's build system dependencies to figure
out what to rebuild.
 * See which test object files were modified.
 * Build a WineTest executable that only includes the relevant test executables
and somehow bake into it the exact list of tests to run.

A side effect would be that while before changing a header file in /include
would not have had any impact on which test to run, with this system we may end
up re-running every single tests (which might actually be the right thing to
do, though rarely).