6ad0810393
Summary: Makes the Comparator class into a Customizable object. Added/Updated the CreateFromString method to create Comparators. Added test for using the ObjectRegistry to create one. Pull Request resolved: https://github.com/facebook/rocksdb/pull/8336 Reviewed By: jay-zhuang Differential Revision: D28999612 Pulled By: mrambacher fbshipit-source-id: bff2cb2814eeb9fef6a00fddc61d6e34b6fbcf2e