[arm] Use EABI unwind library

[Mark Mitchell]

Richard Earnshaw wrote:

> That still creates some problems, because although it's the same as an
> FSF release, it's not *the FSF* release, which is what a lot of
> developers want (and they want to use the same toolchain for all
> targets).

Yes, I understand.

The ideal outcome here is that RTH becomes comfortable with the patch, 
or that we find a way to modify the patch so that he is comfortable with it.

-- 
Mark Mitchell
CodeSourcery, LLC
mark@codesourcery.com