$NetBSD$

Deal with a failure specific to Clang.

--- CMakeLists.txt.orig	2023-09-14 18:14:59.412927438 -0700
+++ CMakeLists.txt	2023-09-14 18:15:15.078501008 -0700
@@ -356,6 +356,7 @@
 		add_definitions(-Wno-nullability-completeness)
 		add_definitions(-Wno-tautological-pointer-compare)
 		add_definitions(-Wno-deprecated-register)
+		add_definitions(-Wno-c++11-narrowing)
 	endif()
 
 	if(USE_ASAN)