This is #1 in a series of patches to enable the "compile" tests in the gfortran test suite (this splits the large patch from here into smaller pieces).
This moves the lists of disabled tests into separate files.
The goal is to have a script that is periodically run to enable the disabled tests as flang becomes more feature-complete. Keeping the lists as a separate file should make it easier for a script and it will avoid modifying the cmake files themselves as tests are removed from the disabled list.