dwarf2 unwind breakage

[Richard Henderson]

Please build with --enable-oldest-abi=2.3.4 and notice that
size_of_encoded_value and read_encoded_value_with_base come
out undefined libc.so, and used in framestate.o.

I suppose the _LIBC frobbery here is supposed to get these
defined only once in libc.so?  Might I suggest, then, that
we instead have a unwind-pe.c that provides all of these
functions.  I would also guess that we currently don't do
the right thing namespace-wise in libc.a.



r~