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

[Glenn Morris <rgm@gnu.org>]

Eli Zaretskii wrote:

>> 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.

(I didn't look at the details of this case, but autoloading variables
tends to just dump the entire definition in the target file, so that
might not help.)

Do note that

time ./src/emacs -Q -batch -l ./lisp/isearch.el

takes ~ 90 seconds here (versus ~ 0.1 sec for the .elc version).

So it's still leaving a time-bomb around if anyone ever loads the
uncompiled version of wherever that code ends up.

(Why is it so dog slow?)