What is an example of a system like MCAS?
Irrespective of 737 MAX MCAS, I haven't seen similar decision relying on a single sensor on 777 or on 757.

Similarly I found nothing similar on Airbus 320, 330, 340, 350, or 380. On these Airbuses, 3 sensors are used for critical decisions, thus the faulty sensor is isolated by voting the data. If the 3 sensors are diverging (no 2 sensors giving similar data), the system goes into safe degraded mode, and the pilots are informed by automatic displayed message.