Summary:
Fix a use-after-move issue in block.cc and added some unit tests.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11505
Test Plan:
```
make all check
./block_test
```
Reviewed By: ltamasi
Differential Revision: D46506188
Pulled By: jowlyzhang
fbshipit-source-id: 316ed8ddd221c00b2bce2cf9fd47eea686cd74a5
Summary:
See new NOTE in HISTORY.md and unreleased_history/README.txt
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11481
Test Plan: some manual testing on my CentOS 8 system
Reviewed By: jaykorean
Differential Revision: D46233342
Pulled By: pdillinger
fbshipit-source-id: daf59cf3dc907f450b469090dcc481a30a7d7c0d