This is as partial import of upstream's
9b05cbc33e7895ed033b1119e300782d9e0cf23c. It includes the perlasm changes, but
not the CPU feature detection bits as we do those differently. This is largely
so we don't diverge from upstream, but it'll help with iOS assembly in the
future.
sha512-armv8.pl is modified slightly from upstream to switch from conditioning
on the output file to conditioning on an extra argument. This makes our
previous change from upstream (removing the 'open STDOUT' line) more explicit.
BUG=338886
Change-Id: Ic8ca1388ae20e94566f475bad3464ccc73f445df
Reviewed-on: https://boringssl-review.googlesource.com/4405
Reviewed-by: Adam Langley <agl@google.com>
