The bill is extremely copy/paste unfriendly, but the full text is here: https://www.scribd.com/document/363309136/Republican-Tax-Bill#download&from_embed
The relevant section starts on page 295.
16 (a) IN GENERAL.—Any compensation which is de-
17 ferred under a nonqualified deferred compensation plan
18 shall be includible in the gross income of the person who
19 performed the services to which such compensation relates
20 when there is no substantial risk of forfeiture of the
rights
21 of such person to such compensation.
24 The term 'nonqualified deferred compensation
25 plan' shall include any plan that provides—
1 ''(i) a right to compensation based on
2 the value of, or appreciation in value of, a
3 specified number of equity units of the
4 service recipient, whether paid in cash or
5 equity, or
6 ''(ii) stock appreciation rights or stock
7 options.