Airbus aircraft have a flight envelope protection, that means it does not allow you to pitch up higher than 30 degrees, or pitch down below -15 degrees, you cannot bank more than 67 degrees and if you let go of the stick it returns you into a window of +/- 33 degrees of bank. It also has an active stall protection, over-stress protection (high g-load) as well as an overspeed protection. You cannot overwrite these commands of the computer unless you shut off several computers and return to the so called alternate or direct law. This is fully simulated in Aerofly FS.
The newer Boeing aircraft like the 777 and 787 also have some fly-by-wire features such as a load-factor command and a pitch assistance during turns (no need to pull elevator during a turn) and the bank angle is also kept within limits if you fly hands off. It also introduces a nose down tendency at low speed so that a stall is harder to get into and it also has a nose up tendency in high speed. But you can always overwrite these features in a Boeing so if you want to you can fly a roll or a loop, you can stall it or overspeed it. This is also fully simulated in Aerofly FS.
MCAS is a different thing though. The maneuvering characteristics augmentation system (MCAS) is a system that improves the handling of the aircraft in certain flight regimes. For the 737 MAX it improves the stall handling in a stall so that it is easier to get out of the stall. On other aircraft like the DC-8 also use MCAS but to improve handling near the high speed Mach tuck. The Boeing 707 and KC-46 (derived from the Boeing 767) also have an MCAS system.
I actually already implemented the MCAS system for the upcoming 737 MAX and according to the documentation that I could find the 737 MCAS was designed to activate in steep turns at high g-load and with high angle of attack. The aircraft would then trim down to reduce the pitch up tendency and to make it more stable. This will also be fully simulated in Aerofly FS, or at least the new and improved MCAS system that uses two angle of attack sensors.