backport #18606 - Add a dummy function to grpc cfstream library
diff --git a/src/core/lib/iomgr/cfstream_handle.cc b/src/core/lib/iomgr/cfstream_handle.cc
index 87b7b9f..06b60f8 100644
--- a/src/core/lib/iomgr/cfstream_handle.cc
+++ b/src/core/lib/iomgr/cfstream_handle.cc
@@ -173,4 +173,11 @@
   }
 }
 
+#else
+
+/* Creating a dummy function so that the grpc_cfstream library will be
+ * non-empty.
+ */
+void CFStreamDummy() {}
+
 #endif