Reland "SkZip - synchronized indexing of several pointers"

This is a reland of f3c4a829c64f6ef2177f86603366c6df9fe801e1

Original change's description:
> SkZip - synchronized indexing of several pointers
>
> This is the mechanism for syncing a bunch of things with
> contiguous memory like vector<>, array<> and SkSpan<>.
>
> In a following CL, a convenience function SkMakeZip will
> easily convert most containers into a zip.
>
> Change-Id: Icda5b1774ae21c4c163a663f6d2b0f119f63ccba
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/240200
> Commit-Queue: Herb Derby <herb@google.com>
> Reviewed-by: Ben Wagner <bungeman@google.com>

Change-Id: I7d1a91a9c35dde721147bb3c1f23c9b3a8d59d04
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/242476
Reviewed-by: Ben Wagner <bungeman@google.com>
Commit-Queue: Herb Derby <herb@google.com>
4 files changed