In order to reuse code buffers, when invalidating we will no longer be
able to invalidate code while inside the code we are invalidating.
Changes the IR operation to be a block ender itself and control jumping
to the new RIP. This way it can invalidate from the dispatcher and just
restart JIT execution.
Have it treated as a block terminator IR and instead of doing
syscall+exitfunction, just do syscall and jump in to the dispatcher.
This is necessary for code invalidation and reuse for code that is stuck
in long running syscalls. We'll need to do something similar for thunks
later, although the recursive nature of thunk+callback can make that a
little squirrely.
Justin Becker