While we currently offer support for building with the undefined behavior sanitizer, it doesn't currently work as a diagnostic tool, due to a few issues:

• We haven't scrubbed all of the flagged issues, so we can't make it fail-fast yet.
• Some libraries, especially those in third_party like v8, may issue diagnostics under ubsan that we either can't or don't want to address
• Some implicit dependency cycles in the LIBDEPS graph cause linking errors when building with the undefined behavior sanitizer, but those edges cannot be made explicit because it trips the cycle detector.

This ticket exists to track work towards fixing these various issues so that we can get green fail-fast undefined behavior sanitizer builds up on the CI system.