[GenericSigBuilder] Archetypes no longer make it to this path. NFC

lib/AST/GenericSignatureBuilder.cpp

@@ -1916,7 +1916,6 @@ bool GenericSignatureBuilder::addSameTypeRequirementToConcrete(
   // Make sure the concrete type fulfills the requirements on the archetype.
   // FIXME: Move later...
   DenseMap<ProtocolDecl *, ProtocolConformanceRef> conformances;
-  if (!Concrete->is<ArchetypeType>()) {
   CanType depTy = rep->getDependentType({ }, /*allowUnresolved=*/true)
                     ->getCanonicalType();
   for (auto &conforms : rep->getConformsTo()) {
@@ -1945,7 +1944,6 @@ bool GenericSignatureBuilder::addSameTypeRequirementToConcrete(
                                                 : nullptr);
     updateRequirementSource(conforms.second, concreteSource);
   }
-  }
 
   // Record the requirement.
   rep->ConcreteType = Concrete;