Fix tmOptimizedBind to avoid quadratic blowup#936

tabareau merged 1 commit intoMetaRocq:coq-8.16MetaRocq/metarocq:coq-8.16from

JasonGross:coq-8.16+fix-opt-bind-perfJasonGross/metacoq:coq-8.16+fix-opt-bind-perfCopy head branch name to clipboard