Thanks for proper dependency checking in the testsuite

[Chris Johns]

Hi,

This is a big thank you to Sebastian for the clean up work in the build system
so we have proper dependencies to the tests in the testsuite against the cpukit
and other libraries. This has been missing for years, even decades. Working on
the build system is one of those areas in RTEMS that does not attract wide
attention or funding and yet is it so important to all developers and so all users.

Sebastian, thank you.

Chris