Merge pull request swiftlang#36630 from adrian-prantl/74503567

Author: swift-ci

lib/ClangImporter/ImportType.cpp

@@ -2351,6 +2351,8 @@ ImportedType ClangImporter::Implementation::importMethodParamsAndReturnType(
     if (kind == SpecialMethodKind::NSDictionarySubscriptGetter &&
         paramTy->isObjCIdType()) {
       swiftParamTy = SwiftContext.getNSCopyingType();
+      if (!swiftParamTy)
+        return {Type(), false};
       if (optionalityOfParam != OTK_None)
         swiftParamTy = OptionalType::get(swiftParamTy);