Merge pull request #41934 from bnbarham/add-empty-abi-feature

[Option] Add feature flag for empty ABI descriptors

Author: bnbarham

lib/Option/features.json

@@ -17,6 +17,9 @@
     },
     {
       "name": "no-warn-superfluous-index-unit-path"
+    },
+    {
+      "name": "empty-abi-descriptor"
     }
   ]
 }