Add Virtus::InstanceMethods#get_attributes.
Add Virtus::InstanceMethods#get_attributes.

This ignores privacy, similarly to #set_attributes.

XescuGC/virtus,faucct/virtus,mallikarjunayaddala/virtus,reevoo/virtus,dslh/virtus,kristianmandrup/virtus,JustMikey/virtus,baojjeu/virtus,macressler/virtus,artemeff/virtus,lgierth/virtus,hapiben/virtus,solnic/virtus,nuclearsandwich/virtus