Summary:
- In `db_stress`, support choosing index type and whether to enable filter partitioning, and randomly set those options in crash test
- When partitioned filter is enabled by crash test, force partitioned index to also be enabled since it's a prerequisite
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4020
Test Plan:
currently this is blocked on fixing the bug that crash test caught:
```
$ TEST_TMPDIR=/data/compaction_bench python ./tools/db_crashtest.py blackbox --simple --interval=10 --max_key=10000000
...
Verification failed for column family 0 key 937501: Value not found: NotFound:
Crash-recovery verification failed :(
```
Differential Revision: D8508683
Pulled By: maysamyabandeh
fbshipit-source-id: 0337e5d0558bcef26b1f3699f47265a2c1e99629