Make missing libunwind fatal on NetBSD

Author: krytarowski

src/pal/src/configure.cmake

@@ -951,7 +951,7 @@ elseif(CMAKE_SYSTEM_NAME STREQUAL FreeBSD)
 elseif(CMAKE_SYSTEM_NAME STREQUAL NetBSD)
   if(NOT HAVE_LIBUNWIND_H)
     unset(HAVE_LIBUNWIND_H CACHE)
-    message(WARNING "Cannot find libunwind. Try installing libunwind8 and libunwind8-dev (or the appropriate packages for your platform)")
+    message(FATAL_ERROR "Cannot find libunwind. Try installing libunwind8 and libunwind8-dev (or the appropriate packages for your platform)")
   endif()
   if(NOT HAVE_BSD_UUID_H)
     unset(HAVE_BSD_UUID_H CACHE)