ClangImporter: Don't call getDirectlyInheritedNominalTypeDecls() on a protocol

Author: slavapestov

lib/ClangImporter/ImportDecl.cpp

@@ -5913,6 +5913,9 @@ SwiftDeclConverter::importSwiftNewtype(const clang::TypedefNameDecl *decl,
     if (!proto)
       return false;
 
+    if (auto *computedProto = dyn_cast<ProtocolDecl>(computedNominal)) {
+      return (computedProto == proto || computedProto->inheritsFrom(proto));
+    }
     // Break circularity by only looking for declared conformances in the
     // original module, or possibly its overlay.
     if (conformsToProtocolInOriginalModule(computedNominal, proto)) {