CI: Intermittent failure in exit_race

https://buildkite.com/julialang/rr/builds/220#1e888f67-0888-451f-be5a-1a11ada9d857

528/2761 Test  #954: exit_race .........................................................***Failed  Error regular expression found in output. Regex=[FAILED]  3.25 sec

source_dir/src/test/util.sh: line 245: 24347 Aborted                 _RR_TRACE_DIR="$workdir" test-monitor $TIMEOUT record.err $RR_EXE $GLOBAL_OPTIONS record $LIB_ARG $RECORD_ARGS "$exe" $exeargs > record.out 2> record.err

Test 'exit_race' FAILED: : error during recording:

--------------------------------------------------

[FATAL /cache/build/exclusive-amdci3-0/julialang/rr/src/RecordSession.cc:1854:process_syscall_entry()] 

 (task 25282 (rec:25282) at time 198)

 -> Assertion `t->desched_rec() || is_rrcall_notify_syscall_hook_exit_syscall( t->regs().original_syscallno(), t->arch()) || t->ip() == t->vm() ->privileged_traced_syscall_ip() .increment_by_syscall_insn_length(t->arch())' failed to hold. Stashed signal pending on syscall entry when it shouldn't be: {signo:SIGSTKFLT,errno:SUCCESS,code:sicode(1)}; IP=0x54071adaa9b7

Start by reviewing the intermittent exit_race failure in the linked Buildkite log and the test support in source_dir/src/test/util.sh, especially around line 245. Then inspect the assertion at RecordSession.cc:1854 and run the exit_race test to establish reproducibility; done means identifying and fixing the intermittent recording failure with the test passing reliably.