Summary: In a recent change, crash_test can put data under TEST_TMPDIR. However, the directory is not cleaned before running the test, which may cause unexpected results. Clean it.
Test Plan: Run white and black box crash test against non-existing, or non-empty but not compactible DBs, and make sure it works as expected.
Reviewers: kradhakrishnan, rven, yhchiang, IslamAbdelRahman
Reviewed By: IslamAbdelRahman
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D43515
cf3e05304f