w=4 appears to be the correct answer for P-224 through P-521. There's
nominally some optimizations in here for 70- and 20-bit primes, but
that's absurd.
Change-Id: Id4ccec779b17e375e9258c1784e46d7d3651c59a
Reviewed-on: https://boringssl-review.googlesource.com/27707
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
Reviewed-by: Adam Langley <agl@google.com>