frame unwinding patches

[Mark Wielaard]

Hi,

I put all three frame pointer unwinding fallback patches on
the mjw/fp-unwind branch. I'll also sent them to the list using
git send-mail --annotate taking out the binary file patches.
Hopefully that will make them appear on the list, bypassing the
spam filters.

[PATCH 1/3] Add frame pointer unwinding as fallback on x86_64
[PATCH 2/3] Add frame pointer unwinding as fallback on arm
[PATCH 3/3] Add frame pointer unwinding for aarch64

I had to hand apply a few things because of whitespace adjustments.
Hopefully I did it right and this is how Ulf intended the patches.
If not, my apologies, and please let me know what changes you did
intend.

Cheers,

Mark