Run 0 tests the default configuration of Frama-C: no downcast alarms, except
for pointers.
Runs 1 to 3 correspond to the previous run with successive -then, and test:
- emission of signed downcast alarms (option -warn-signed-downcast)
- emission of unsigned downcast alarms (option -warn-unsigned-downcast)
- the relaxed semantics of the Eva option -eva-warn-signed-converted-downcast
Run 4 disables all downcast alarms, including downcast of pointer values.