Summary:
Continuing work from https://github.com/facebook/rocksdb/issues/13965. Here I'm migrating the "next with shift" kind of bit field and for that I've added an API for atomic additive transformations that can be combined into a single atomic update for multiple fields. (I implemented more features than needed, just in case they are needed someday and to demonstrate what is possible.)
Pull Request resolved: https://github.com/facebook/rocksdb/pull/14027
Test Plan: BitFields unit test updated/added, existing HCC tests
Reviewed By: xingbowang
Differential Revision: D83895094
Pulled By: pdillinger
fbshipit-source-id: e4487f34f5607b20f94b85a645ca654e6401e35d
4951494a27