Function lua_pushthread

third-party/lua-5.5.0/src/lapi.c:655–661

LUA_API int lua_pushthread (lua_State *L) {
  lua_lock(L);
  setthvalue(L, s2v(L->top.p), L);
  api_incr_top(L);
  lua_unlock(L);
  return (mainthread(G(L)) == L);
}