RFC: target macro->hook migration idea

[DJ Delorie]

> I have one concern with this part, which is, there are a bunch of
> macros that are used mostly - or even entirely - by other macros.
> Things like ASM_OUTPUT_INT.  What do you think we should do with them?
> 
> And another concern with this part: I'm leery of trying to design
> target hooks /a priori/.  Every time I've done target hook
> conversions, the proper form has emerged organically from the morass.
> I don't really have a better suggestion, though.

I wasn't planning on changing the interface, beyond a few hooks that
I'd like to add extra parameters to.  I was going to mechanically
convert the macros to functions, keeping the same names, args, and
return types.

IMHO changing the API is a separate issue.

When I said "design the target structure" I meant organizing the hooks
into reasonable categories, not changing the hooks themselves.