Flaky crash runtime_entry.cc: 4111: error: unreachable code

[alexmarkov]

From log:

/=====================================================================================================\
| vm-linux-release-arm-qemu:vm/dart/isolates/fibonacci_call_test broke (Pass -> Crash, expected Pass) |
\=====================================================================================================/

--- Command "vm_compile_to_kernel" (took 12.000518s):
DART_CONFIGURATION=ReleaseXARM QEMU_LD_PREFIX=/usr/arm-linux-gnueabihf/ /b/s/w/ir/cache/builder/sdk/pkg/vm/tool/gen_kernel --no-aot --platform=out/ReleaseXARM/vm_platform.dill -o /b/s/w/ir/cache/builder/sdk/out/ReleaseXARM/generated_compilations/vm-linux-release-arm-qemu/runtime_tests_vm_dart_isolates_fibonacci_call_test/out.dill /b/s/w/ir/cache/builder/sdk/runtime/tests/vm/dart/isolates/fibonacci_call_test.dart -Dtest_runner.configuration=vm-linux-release-arm-qemu --packages=/b/s/w/ir/cache/builder/sdk/.dart_tool/package_config.json -Ddart.vm.product=false -Ddart.vm.asan=false -Ddart.vm.msan=false -Ddart.vm.tsan=false

exit code:
0

--- Command "vm" (took 10.000250s):
DART_CONFIGURATION=ReleaseXARM QEMU_LD_PREFIX=/usr/arm-linux-gnueabihf/ TEST_COMPILATION_DIR=/b/s/w/ir/cache/builder/sdk/out/ReleaseXARM/generated_compilations/vm-linux-release-arm-qemu/runtime_tests_vm_dart_isolates_fibonacci_call_test qemu-arm out/ReleaseXARM/dart --disable_heap_verification --no_check_function_fingerprints -Dtest_runner.configuration=vm-linux-release-arm-qemu --ignore-unrecognized-flags --packages=/b/s/w/ir/cache/builder/sdk/.dart_tool/package_config.json /b/s/w/ir/cache/builder/sdk/out/ReleaseXARM/generated_compilations/vm-linux-release-arm-qemu/runtime_tests_vm_dart_isolates_fibonacci_call_test/out.dill

exit code:
-6

stderr:
../../runtime/vm/runtime_entry.cc: 4111: error: unreachable code
../../runtime/vm/runtime_entry.cc: 4111: error: unreachable code
version=3.11.0-edge (main) (Unknown timestamp) on "linux_arm"
pid=822581, thread=822599, isolate_group=main(0x235fbf0), isolate=fibonacciRecursive(0x3c0460b0)
os=linux, arch=arm, comp=no, sim=no
isolate_instructions=1f6bbc0, vm_instructions=1f6bbc0
fp=3be7e398, sp=3be7e380, pc=2115dcb
  pc 0x02115dcb fp 0x3be7e398 dart::ObjectCopy<dart::SlowObjectCopyBase>::CopyPredefinedInstance+0x26b
Aborting reentrant request for stack trace.

--- Re-run this test:
python3 tools/test.py -n vm-linux-release-arm-qemu vm/dart/isolates/fibonacci_call_test