It has to be noted that doing accurate performance tests can be very
time consuming thus these kind of tests cannot be executed as a normal
unity-tests during development.
Never the less performances are proper requirements and
should definitely be part of a specific suite of tests.
My recommendation is to put
them in a separate unit and to execute them at every total
rebuild of the project. Of course this is a sub optimal trade off but
nobody really wants to wait hours for a performance check at every
recompilation and at the same time performances should be checked at
least once in a while.
In the present case these examples have been made independent program to allow them to be executed individually and to not interfere with the normal building process (that requires to execute every test).