tool.drcachesim.coherence test failed on Travis: "Invalid trace entry type 23 before a bundle"

This happened once on Travis: https://travis-ci.com/DynamoRIO/dynamorio/jobs/295374252

Invalid trace entry type 23 before a bundle

23 is (+1 here b/c 1-based):

$ grep '^ *TRACE_TYPE' clients/drcachesim/common/trace_entry.h | grep -n . | grep 24
24:    TRACE_TYPE_THREAD_EXIT, /**< A thread exit. */