three problems with stor-layout.c.

[Eric Botcazou]

> I think most of these are because in the past (yes I have fixed that!!)
> all 'sizetype' constants were sign-extended (and the signedness,
> that is, TYPE_UNSIGNED (sizetype), was frontend dependend (ugh) and
> then later true, thus unsigned).
> 
> So I think all _SIZE stuff should check fits_uhwi_p and be used as
> uhwi.  But that may have ripple-down effects, so consistently
> using fits_shwi_p and using as shwi is also fine (it just restricts
> the maximum values we accept(?)).

And please make sure to test Ada if you're tweaking this, it's fragile stuff.

-- 
Eric Botcazou