Attempt to fix build errors around missing compression library includes (#7803)

Summary:
This fixes an issue introduced in https://github.com/facebook/rocksdb/pull/7769 that caused many errors about missing compression libraries to be displayed during compilation, although compilation actually succeeded. This PR fixes the compilation so the compression libraries are only introduced where strictly needed.

It likely needs to be merged into the same branches as https://github.com/facebook/rocksdb/pull/7769 which I think are:
1. master
2. 6.15.fb
3. 6.16.fb

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7803

Reviewed By: ramvadiv

Differential Revision: D25733743

Pulled By: pdillinger

fbshipit-source-id: 6c04f6864b2ff4a345841d791a89b19e0e3f5bf7

Bump the version file to 6.15.2 and update HISTORY.md with fix information.

Also, fix a merge issue with .circleci/config.yml (missing
install-cmake-on-macos in commands section)

Fix various small build issues, Java API naming (#7776)

Summary:
* Compatibility with older GCC.
* Compatibility with older jemalloc libraries.
* Remove Docker warning when building i686 binaries.
* Fix case inconsistency in Java API naming (potential update to HISTORY.md deferred)

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7776

Reviewed By: akankshamahajan15

Differential Revision: D25607235

Pulled By: pdillinger

fbshipit-source-id: 7ab0fb7fa7a34e97ed0bec991f5081acb095777d