MMIO: Add a function to check if a given address refers to MMIO registers.
MMIO: Pass pointers to the complex method lambdas when visiting.
x64Emitter: Allow const pointers where it makes sense to do so.
x64ABI: Add two more CallFunction functions (for additional parameter types).
x64Emitter: Add functions to call a C++ std::function from JITed code
JitUtil: Optimize MMIO loads by generating code to directly access a given MMIO.