How to add mesh renderers that share a single material to a list/array?

EDIT: The function described below has been reprogrammed to not use materials to check if floors should be added to the list and instead uses a new method which works well! This question will still be up in case you can use materials to check if items should be added to lists.

My older brother is making a Baldi's Basics Classic decompile and he wants to add floors whose mesh renderers share a single material to an array, but when he play tests the decompile, there are no game objects in "hallwayFloors". How to do that? Here's some code.

             GameObject[] allObjs = UnityEngine.Object.FindObjectsOfType<GameObject>();
             List <GameObject> list = new List<GameObject>(0);
             for (int i = 0; i < allObjs.Length; i++)
             {
                 if (allObjs[i].name == "Floor")
                 {
                     MeshRenderer mr = allObjs[i].GetComponent<MeshRenderer>();
                     if (mr.material == hallwayFloor)
                     {
                         list.Add(allObjs[i]);
                     }
                 }
             }
             hallwayFloors = list.ToArray();

BTW, the decompile's Unity version is 2018.3.9f1, so "material.name" won't work.