The 64-bit version can be fairly straightforwardly translated.
Ironically, this makes 32-bit x86 the first architecture to meet the
goal of constant-time AES-GCM given SIMD assembly. (Though x86_64 could
join by simply giving up on bsaes...)
Bug: 263
Change-Id: Icb2cec936457fac7132bbb5dbb094433bc14b86e
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/35024
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: Adam Langley <agl@google.com>