SpiderMonkey porting into two firefox versions

[email protected] Fri, 4 Aug 2017 03:18:22 -0700 (PDT)

Newsgroups	gmane.comp.mozilla.devel.jseng
Message-ID	<[email protected]>

Hello!

I'm porting spiderMonkey (baseline + ion) on my new architecture.
But my clients want to use firefox 45 (ESR build) and 52.2.1 (also ESR build).

I have some working 51.1 version spiderMonkey engine with my backend.

So, is it painless to update my spiderMonkey 51.1 to 52.2.1 and integrate it into firefox 45 and firefox 52

OR

I have to work on two version of spiderMonkey 45 and 52?