[build] Move unwinder to toplevel libgcc (v2)

[Paolo Bonzini]

On 08/10/2011 06:50 PM, Pedro Alves wrote:
> On Wednesday 10 August 2011 17:05:08, Rainer Orth wrote:
>> >  Paolo Bonzini<bonzini@gnu.org>  writes:
>> >
>>>> >  >>  True: it is called once per multilib.
>>> >  >
>>> >  >  Just to doublecheck, are we sure that unwind.h is always the same?
>> >
>> >  Yep: it's unwind-generic.h for almost all targets, just a few arm
>> >  targets use config/arm/unwind-arm.h for all multilibs.
> Doesn't each multilib get its own build subdir?
> Can't the file be copied there instead and thus get rid of this wart?

It would need an additional per-multilib directory in the include path. 
  It's simpler for now to leave it as is, and it will go away as soon as 
nothing in the gcc directory will need unwind.h.  Rainer has already 
removed countless dependencies between gcc and libgcc, adding one is not 
too bad.

Paolo