* Pushbuffer data is now stored in a member buffer to avoid reallocating
it for each pushbuffer which hampered performance before.
* Don't prefetch pushbuffers as it puts unnecessary load on the guest
thread that is better suited for the GPFIFO thread.
* Clean up some misc code to avoid pointless casts of a 4 byte object
and handle GPFIFO control opcodes.
CircularQueue was looping around too early resulting in the wrong
pushbuffers being used. The debug logging is useful for interpreting the
GPU method call logs.
Exefs loading was changed to check if an NSO exists before trying to
read it, preventing exceptions that get annoying while debugging.
An exceptional signal handler allows us to convert an OS signal into a C++ exception, this allows us to alleviate a lot of crashes that would otherwise occur from signals being thrown during execution of games and be able to handle them gracefully.
bugs
An engine is effectively a HW block in the GPU, the main one is the
Maxwell 3D which is used for 3D graphics. Engines can be bound to
individual subchannels and then methods within them can be called
through pushbuffers.
The engine side of the GPFIO is also included, it currently does nothing
but will need to be extended in the future with semaphores.
