RFA: consolidate DWARF strings into libiberty

[DJ Delorie]

> But given the pushback for even one new library, I think we're
> unnecessarily slowing ourselves down.

I'm not opposed to libiberty becoming the kitchen sink, if that's what
people want.  If it does go that route, my reason for being a
libiberty maintainer no longer applies, and others who are more
kitchen-sink-minded should take over.

The only drawback to adding toplevel libraries is coordinating changes
among the toplevel configury.