fix dyn-pvec-len for hyper-coercions
fix dyn-pvec-len for hyper-coercions

akuhlens/schml,akuhlens/schml,akuhlens/schml,akuhlens/schml,Gradual-Typing/Grift,akuhlens/schml,Gradual-Typing/Grift,Gradual-Typing/Grift,akuhlens/schml,Gradual-Typing/Grift