tool.drcacheoff.burst_replaceall failure on Windows with 2nd thread in simulator results

Looks like we expect one thread, but two are running. Is it one of the Windows pool threads? Why is it only showing up on this one run?

https://github.com/DynamoRIO/dynamorio/runs/5502017781?check_suite_focus=true
```
238: Running postcmd |D:/a/dynamorio/dynamorio/build_debug-internal-64/clients/bin64/drcachesim.exe;-indir;D:/a/dynamorio/dynamorio/build_debug-internal-64/suite/tests/drmemtrace.tool.drcacheoff.burst_replaceall.exe.02076.9096.dir|
238: CMake Error at D:/a/dynamorio/dynamorio/suite/tests/runmulti.cmake:130 (message):
238: output |replace all file functions
238:
238: pre-DR init
238:
238: pre-DR start
238:
238: pre-DR detach
238:
238: processing 15 buffers
238:
238: creating module file
238: .\drmemtrace.tool.drcacheoff.burst_replaceall.exe.02076.9096.dir\raw\modules.log
238:
238:
238: all done
238:
238: Cache simulation results:
238:
238: Core #0 (1 thread(s))
238:
238: L1I stats:
238: Hits: 212,510
238: Misses: 251
238: Compulsory misses: 251
238: Invalidations: 0
238: Miss rate: 0.12%
238: L1D stats:
238: Hits: 78,521
238: Misses: 62
238: Compulsory misses: 100
238: Invalidations: 0
238: Prefetch hits: 24
238: Prefetch misses: 38
238: Miss rate: 0.08%
238:
238: Core #1 (1 thread(s))
238:
238: L1I stats:
238: Hits: 2,577
238: Misses: 168
238: Compulsory misses: 168
238: Invalidations: 0
238: Miss rate: 6.12%
238: L1D stats:
238: Hits: 1,094
238: Misses: 98
238: Compulsory misses: 172
238: Invalidations: 0
238: Prefetch hits: 24
238: Prefetch misses: 74
238: Miss rate: 8.22%
238:
238: Core #2 (0 thread(s))
238:
238: Core #3 (0 thread(s))
238:
238: LL stats:
238:
238: Hits: 3
238: Misses: 576
238: Compulsory misses: 686
238: Invalidations: 0
238: Prefetch hits: 2
238: Prefetch misses: 110
238: Local miss rate: 99.48%
238: Child hits: 294,750
238: Total miss rate: 0.20%
238:
238: | failed to match expected output |replace all file functions
238:
238: pre-DR init
238:
238: pre-DR start
238:
238: pre-DR detach
238:
238: processing [0-9]* buffers
238:
238: creating module file .*
238:
238: all done
238:
238: Cache simulation results:
238:
238: Core #0 \(1 thread\(s\)\)
238:
238: L1I stats:
238: Hits: *[0-9,\.]*
238: Misses: *[0-9,\.]*
238: Compulsory misses: *[0-9,\.]*
238: Invalidations: *0
238:
238: .* Miss rate: [0-3][,\.]..%
238:
238: L1D stats:
238: Hits: *[0-9,\.]*
238: Misses: *[0-9,\.]*
238: Compulsory misses: *[0-9,\.]*
238: Invalidations: *0
238:
238: .* Miss rate: [0-3][,\.]..%
238:
238: Core #1 \(0 thread\(s\)\)
238:
238: Core #2 \(0 thread\(s\)\)
238:
238: Core #3 \(0 thread\(s\)\)
238:
238: LL stats:
238:
238: Hits: *[0-9,\.]*
238: Misses: *[0-9,\.]*
238: Compulsory misses: *[0-9,\.]*
238: Invalidations: *0
238:
238: .* Local miss rate: *[0-9,.]*%
238:
238: Child hits: *[0-9,\.]*
238: Total miss rate: [0-1][,\.]..%
238:
238: |
238:
238:
237/274 Test #238: code_api|tool.drcacheoff.burst_replaceall ....................***Failed 2.44 sec
```