Summary:
Added support for detecting plugins linked in the "plugin/" directory and building them from our Makefile in a standardized way. See "plugin/README.md" for details. An example of a plugin that can be built in this way can be found in https://github.com/ajkr/dedupfs.
There will be more to do in terms of making this process more convenient and adding support for CMake.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7918
Test Plan: my own plugin (https://github.com/ajkr/dedupfs) and also heard this patch worked with ZenFS.
Reviewed By: pdillinger
Differential Revision: D26189969
Pulled By: ajkr
fbshipit-source-id: 6624d4357d0ffbaedb42f0d12a3fcb737c78f758