bug#20887: 'make bootstrap' now verrrry slow due to recent isearch changes

[Eli Zaretskii]

> Date: Wed, 24 Jun 2015 15:28:02 +0100
> From: Artur Malabarba <bruce.connor.am@gmail.com>
> Cc: 20887@debbugs.gnu.org
> 
> Yes, I see why that would cause a problem.
> Does anyone have any idea how we could approach this, then?
> 
> That slow piece code has no need to be compiled so early, but I don't
> know how to avoid that. I can move it to another file, but then
> isearch will need to require that file anyway so the delay will still
> be there.
> 
> Options I see
> 1. I could move the code to a separate file, and then only require
> that file as part of the isearch command, so it wouldn't be loaded at
> compile time.
> 2. I could just save that char-table directly in the file. It would be
> large, but it should speed up the loading by a lot.

I think 1 is better.  Make that variable autoloaded in isearch.el, and
the problem should be solved.