Although it is always possible to destroy and recreate the design to
simulate a power-on reset, this has two drawbacks:
* Black boxes are also destroyed and recreated, which causes them
to reacquire their resources, which might be costly and/or erase
important state.
* Pointers into the design are invalidated and have to be acquired
again, which is costly and might be very inconvenient if they are
captured elsewhere (especially through the C API).
Compared to the C++ API, the C API currently has two limitations:
1. Memories cannot be updated in a race-free way.
2. Black boxes cannot be implemented in C.
whitequark