Function codeclosure

3rd/lua-5.4.3/src/lparser.c:710–714

** codes instruction to create new closure in parent function. ** The OP_CLOSURE instruction uses the last available register, ** so that, if it invokes the GC, the GC knows which registers ** are in use at that time. */

*/
static void codeclosure (LexState *ls, expdesc *v) {
  FuncState *fs = ls->fs->prev;
  init_exp(v, VRELOC, luaK_codeABx(fs, OP_CLOSURE, 0, fs->np - 1));
  luaK_exp2nextreg(fs, v);  /* fix it at the last register */
}


static void open_func (LexState *ls, FuncState *fs, BlockCnt *bl) {