Yanqin Jin 2cdaf5ca5b Add additional checks for three existing unit tests (#8973)
Summary:
With test sync points, we can assert on the equality of iterator value in three existing
unit tests.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8973

Test Plan:
```
gtest-parallel -r 1000 ./db_test2 --gtest_filter=DBTest2.IterRaceFlush2:DBTest2.IterRaceFlush1:DBTest2.IterRefreshRaceFlush
```

make check

Reviewed By: akankshamahajan15

Differential Revision: D31256340

Pulled By: riversand963

fbshipit-source-id: a9440767ab383e0ec61bd43ffa8fbec4ba562ea2
2021-10-01 17:22:37 -07:00
..
2020-06-15 10:47:02 -07:00
2020-12-09 16:02:12 -08:00