Move _changed_functions modification code around.
Move _changed_functions modification code around.

Move the modification to _changed_functions to _scan_irsb() and
_scan_procedure(), since the function address might be changed (see next
commit).

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