CFGBase: remove empty functions at the end of make_functions().
CFGBase: remove empty functions at the end of make_functions().

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