This gives a 15-16% perf boost for 1024-bit RSA keys, but 1024-bit RSA
keys are no longer important enough for this code to carry its weight.
Change-Id: Ia9f0e7fec512c28e90754ababade394c1f11984d
Reviewed-on: https://boringssl-review.googlesource.com/12841
Commit-Queue: David Benjamin <davidben@google.com>
Commit-Queue: Adam Langley <agl@google.com>
Reviewed-by: Adam Langley <agl@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>