pn->pn_op = JSOP_NOP;
NewParseNode(JSContext *cx, JSToken *tok, JSParseNodeArity arity){    JSParseNode *pn;    JS_ARENA_ALLOCATE(pn, &cx->tempPool, sizeof(JSParseNode));    if (!pn)	return NULL;    pn->pn_type = tok->type;    pn->pn_pos = tok->pos;    pn->pn_arity = arity;    pn->pn_next = NULL;    return pn;}