simu - goto handler
simu - optimize a little bit on branch handler
simu - goto handler tested
simu - save and restore + several bug fix
simu - "perform" handler
simu - rearrange some modules
simu - rearrange modules
simu - clean up
simu - extract register name on restore
simu - build-and-execute shortcuts
keep legacy implemenatation in one file
simu - a minimal impl for comparison