run_regression.py to fail on invalid requirements (#5264)

run_regression.py to fail on invalid requirements (#5264)

Currently, the following test is skipped when running ctest:

 ; REQUIRES: symfpuuuu
 ; EXPECT: sat
 (set-logic ALL)
 (assert true)
 (check-sat)
I think it is better for such a test to fail, because otherwise it might never run without anyone noticing (this almost happened to me here: c7e277b).

This PR makes such tests to fail by checking whether the REQUIRES value is valid. No regressions fail as a result.

Co-authored-by: Mathias Preiner mathias.preiner@gmail.com