[RFC] Adding libbacktrace

[Nick Clifton]

Hi Andrew,

> There seems to be a general problem here that our top-level Makefile
> scripts will try to build target modules if they are available, even
> when that's not the right thing to do for binutils-gdb.
> 
> Any ideas welcome :)

Punt to gcc. :-)

More specifically, since gcc owns the so called "master" version of
the configure script, they should be the ones to fix this problem.

But I suspect that fixing this might not be at the top of their priority
list, but if you appeal to Ian Lance Taylor directly ypu may get a better
response.

Cheers
   Nick