allow custom typechecker in SimplifyDefUse pass (#1807)
allow custom typechecker in SimplifyDefUse pass (#1807)


p4lang/p4c,hanw/p4c,hanw/p4c,p4lang/p4c,mbudiu-vmw/p4c-clone,mbudiu-vmw/p4c-clone,mbudiu-vmw/p4c-clone,p4lang/p4c,hanw/p4c,p4lang/p4c,p4lang/p4c,hanw/p4c,mbudiu-vmw/p4c-clone