[Yhc] Needless yhc recompiles

[Neil Mitchell]

Hi Thorkil,

> I believe that I have a definite case of yhc recompiling a lot of things
> needlessly. Unfortunately, quite a lot of code is involved. Are there known
> limitations in this area or should I try to reduce to a manageable size?

Not as far as I know - if the .hi file changes then lots of things
will be rebuilt, but only things which import a given module. Tom
might be able to comment further, as he wrote the original code.

Even if you can only come up with a big example for now, just attached
it on the wiki and someone can hunt it down later.

Thanks

Neil