Re: eval-when-compile vs defconst

[Richard Stallman]

    Surely it's there to avoid calling (and loading) `regexp-opt' at load
    time, and the concat is merely along for the ride?  Unless the optimizer
    already evaluates calls to `regexp-opt' on quoted lists, it seems useful
    to me.

Indeed, to avoid loading regexp-opt might be worth the trouble.
(The time of running it isn't significant.)

So if it succeeds in doing that, it is worth keeping.