Algorithmically faster than `std::unordered_[map|set]`, and use a small vector internally reducing heap allocations.
Change-Id: I9c0b00468272d9d7c72ab077d832d66d1368500c
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/98123
Commit-Queue: Ben Clayton <bclayton@google.com>
Reviewed-by: Dan Sinclair <dsinclair@chromium.org>