32-bit tool.drcacheoff.burst_threads fails with "Cannot correctly handle received signal 11"

This happened 2x in a row on GA CI in PR #4957:

2021-06-22T22:54:46.2847759Z 295: CMake Error at /home/runner/work/dynamorio/dynamorio/suite/tests/runmulti.cmake:106 (message):
2021-06-22T22:54:46.2848637Z 295:   *** cmd failed (40): pre-DR init
2021-06-22T22:54:46.2849042Z 295: 
2021-06-22T22:54:46.2849496Z 295:   pre-DR start
2021-06-22T22:54:46.2849856Z 295: 
2021-06-22T22:54:46.2850331Z 295:   pre-DR detach
2021-06-22T22:54:46.2850663Z 295: 
2021-06-22T22:54:46.2851124Z 295:   pre-DR init
2021-06-22T22:54:46.2851475Z 295: 
2021-06-22T22:54:46.2851915Z 295:   pre-DR start
2021-06-22T22:54:46.2852271Z 295: 
2021-06-22T22:54:46.2852741Z 295:   pre-DR detach
2021-06-22T22:54:46.2853069Z 295: 
2021-06-22T22:54:46.2853418Z 295:   <Application
2021-06-22T22:54:46.2854440Z 295:   /home/runner/work/dynamorio/dynamorio/build_debug-internal-32/clients/bin32/tool.drcacheoff.burst_threads
2021-06-22T22:54:46.2855393Z 295:   (21574).  Cannot correctly handle received signal 11 in thread 21575:
2021-06-22T22:54:46.2855986Z 295:   default action in native thread.>

In my Ubuntu 16.04 VM: I can reproduce this in TOT, so unrelated to that PR. It reproduces 5x out of 100.