luaK_getlabel
luaK_getlabel(fs);
luaK_getlabel(fs); /* those instructions may be jump targets */
final = luaK_getlabel(fs);
LUAI_FUNC int luaK_getlabel (FuncState *fs);
whileinit = luaK_getlabel(fs);
int repeat_init = luaK_getlabel(fs);