Bug fix in Block: cache opt_level.
Bug fix in Block: cache opt_level.

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