Summary:
It is useful to run UBSAN before merging a PR. This commit adds it. We see warning for stl_tree.h, suppress the warning to make it work.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7112
Test Plan: See the CI to succeed. Manually ingest a UBSAN warning and see it got reported.
Reviewed By: pdillinger
Differential Revision: D22490519
fbshipit-source-id: e4495a0c78a3e2dae7dbf294da79585e141cbb66
