remove SendAndBlockLink::duplicate() (sorbet#8424)

Author: froydnj

core/Types.h

@@ -937,7 +937,6 @@ class SendAndBlockLink {
 
     SendAndBlockLink(NameRef fun, std::vector<ArgInfo::ArgFlags> &&argFlags);
     std::optional<int> fixedArity() const;
-    std::shared_ptr<SendAndBlockLink> duplicate();
 };
 
 class TypeAndOrigins final {

core/types/types.cc

@@ -781,11 +781,6 @@ TypePtr AndType::make_shared(const TypePtr &left, const TypePtr &right) {
 SendAndBlockLink::SendAndBlockLink(NameRef fun, vector<ArgInfo::ArgFlags> &&argFlags)
     : argFlags(move(argFlags)), fun(fun) {}
 
-shared_ptr<SendAndBlockLink> SendAndBlockLink::duplicate() {
-    auto copy = *this;
-    return make_shared<SendAndBlockLink>(move(copy));
-}
-
 optional<int> SendAndBlockLink::fixedArity() const {
     optional<int> arity = 0;
     for (auto &arg : argFlags) {