Add fast stack trace on ARM.

Port of the fast stack trace feature to ARM.
Add fast stack trace on AArch64.

Port of the fast stack trace feature to AArch64.
Merge branch 'fast-stack-trace-aarch64' of https://github.com/fillexen/libunwind
Merge branch 'fast-stack-trace-arm' of https://github.com/fillexen/libunwind
One time whitespace fixup.

for f in $(find src include -name '*.[ch]'); do
  expand -t 8 $f > $tmp; mv $tmp $f;
done