move _uc_regs, prefix, and const into properties to avoid pickling problems in cpython
move _uc_regs, prefix, and const into properties to avoid pickling problems in cpython

angr/angr,chubbymaggie/angr,angr/simuvex,chubbymaggie/angr,tyb0807/angr,angr/angr,chubbymaggie/simuvex,schieb/angr,iamahuman/angr,f-prettyland/angr,chubbymaggie/angr,f-prettyland/angr,iamahuman/angr,f-prettyland/angr,chubbymaggie/simuvex,schieb/angr,iamahuman/angr,axt/angr,tyb0807/angr,axt/angr,chubbymaggie/simuvex,axt/angr,schieb/angr,angr/angr,tyb0807/angr