Update pre-generated bindings code.

src/pre_generated-zmq.nobj.c

@@ -786,7 +786,18 @@ static const char zmq_ffi_lua_code[] = "local error = error\n"
 "local OBJ_TYPE_FLAG_WEAK_REF	= 1\n"
 "local OBJ_TYPE_SIMPLE					= 2\n"
 "\n"
-"ffi.cdef[[\n"
+"local function ffi_safe_cdef(block_name, cdefs)\n"
+"	local fake_type = \"struct sentinel_\" .. block_name .. \"_ty\"\n"
+"	local stat, size = pcall(ffi.sizeof, fake_type)\n"
+"	if stat and size > 0 then\n"
+"		-- already loaded this cdef block\n"
+"		return\n"
+"	end\n"
+"	cdefs = fake_type .. \"{ int a; int b; int c; };\" .. cdefs\n"
+"	return ffi.cdef(cdefs)\n"
+"end\n"
+"\n"
+"ffi_safe_cdef(\"LuaNativeObjects\", [[\n"
 "\n"
 "typedef struct obj_type obj_type;\n"
 "\n"
@@ -811,7 +822,7 @@ static const char zmq_ffi_lua_code[] = "local error = error\n"
 "	uint32_t flags;  /**< lua_own:1bit */\n"
 "} obj_udata;\n"
 "\n"
-"]]\n"
+"]])\n"
 "\n"
 "-- cache mapping of cdata to userdata\n"
 "local weak_objects = setmetatable({}, { __mode = \"v\" })\n"