test_pthread_proxying_canceled_work: RuntimeError: operation does not support unaligned accesses

I've seen this a few times in CI recently.

```
======================================================================
FAIL: test_pthread_proxying_canceled_work (test_core.lsan)
----------------------------------------------------------------------
Traceback (most recent call last):
File "/home/chrome-bot/.cache/vpython-root.1000/store/cpython+tkj8tpr2n0oj8m0t270p0m71s0/contents/lib/python3.8/unittest/case.py", line 60, in testPartExecutor
yield
File "/home/chrome-bot/.cache/vpython-root.1000/store/cpython+tkj8tpr2n0oj8m0t270p0m71s0/contents/lib/python3.8/unittest/case.py", line 676, in run
self._callTestMethod(testMethod)
File "/home/chrome-bot/.cache/vpython-root.1000/store/cpython+tkj8tpr2n0oj8m0t270p0m71s0/contents/lib/python3.8/unittest/case.py", line 633, in _callTestMethod
method()
File "/b/s/w/ir/x/w/install/emscripten/test/common.py", line 348, in decorated
f(self, *args, **kwargs)
File "/b/s/w/ir/x/w/install/emscripten/test/test_core.py", line 2484, in test_pthread_proxying_canceled_work
self.do_run_in_out_file_test(
File "/b/s/w/ir/x/w/install/emscripten/test/common.py", line 1931, in do_run_in_out_file_test
output = self._build_and_run(srcfile, expected, **kwargs)
File "/b/s/w/ir/x/w/install/emscripten/test/common.py", line 1969, in _build_and_run
js_output = self.run_js(js_file, engine, args,
File "/b/s/w/ir/x/w/install/emscripten/test/common.py", line 1556, in run_js
self.fail('JS subprocess failed (%s): %s (expected=%s). Output:\n%s' % (error.cmd, error.returncode, assert_returncode, ret))
File "/home/chrome-bot/.cache/vpython-root.1000/store/cpython+tkj8tpr2n0oj8m0t270p0m71s0/contents/lib/python3.8/unittest/case.py", line 753, in fail
raise self.failureException(msg)
AssertionError: JS subprocess failed (/b/s/w/ir/cache/builder/emscripten-releases/node-v20.14.0-linux-x64/bin/node --stack-trace-limit=50 --trace-uncaught /b/s/w/ir/x/t/emtest_jarzrh1c/emscripten_test_lsan_7vafnkyn/test_pthread_proxying_canceled_work.js): 1 (expected=0). Output:
testing cancel followed by proxy
wasm://wasm/test_pthread_proxying_canceled_work.wasm-0010c28e:1

RuntimeError: operation does not support unaligned accesses
at test_pthread_proxying_canceled_work.wasm.a_cas (wasm://wasm/test_pthread_proxying_canceled_work.wasm-0010c28e:wasm-function[186]:0x5205)
at test_pthread_proxying_canceled_work.wasm.__private_cond_signal (wasm://wasm/test_pthread_proxying_canceled_work.wasm-0010c28e:wasm-function[192]:0x52a9)
at test_pthread_proxying_canceled_work.wasm.pthread_cond_signal (wasm://wasm/test_pthread_proxying_canceled_work.wasm-0010c28e:wasm-function[174]:0x4ade)
at test_pthread_proxying_canceled_work.wasm.emscripten_proxy_finish (wasm://wasm/test_pthread_proxying_canceled_work.wasm-0010c28e:wasm-function[128]:0x3c87)
at test_pthread_proxying_canceled_work.wasm.call_then_finish_task (wasm://wasm/test_pthread_proxying_canceled_work.wasm-0010c28e:wasm-function[141]:0x422d)
at test_pthread_proxying_canceled_work.wasm.call_with_ctx (wasm://wasm/test_pthread_proxying_canceled_work.wasm-0010c28e:wasm-function[136]:0x40de)
at test_pthread_proxying_canceled_work.wasm.em_task_queue_execute (wasm://wasm/test_pthread_proxying_canceled_work.wasm-0010c28e:wasm-function[110]:0x3506)
at test_pthread_proxying_canceled_work.wasm.receive_notification (wasm://wasm/test_pthread_proxying_canceled_work.wasm-0010c28e:wasm-function[119]:0x3873)
at test_pthread_proxying_canceled_work.wasm.em_task_queue_execute (wasm://wasm/test_pthread_proxying_canceled_work.wasm-0010c28e:wasm-function[110]:0x3506)
at test_pthread_proxying_canceled_work.wasm._emscripten_check_mailbox (wasm://wasm/test_pthread_proxying_canceled_work.wasm-0010c28e:wasm-function[291]:0x702d)
at /b/s/w/ir/x/t/emtest_jarzrh1c/emscripten_test_lsan_7vafnkyn/test_pthread_proxying_canceled_work.js:1117:12
at callUserCallback (/b/s/w/ir/x/t/emtest_jarzrh1c/emscripten_test_lsan_7vafnkyn/test_pthread_proxying_canceled_work.js:4730:5)
at checkMailbox (/b/s/w/ir/x/t/emtest_jarzrh1c/emscripten_test_lsan_7vafnkyn/test_pthread_proxying_canceled_work.js:4761:5)
Thrown at:
at $a_cas (wasm://wasm/test_pthread_proxying_canceled_work.wasm-0010c28e:1:20998)
at $__private_cond_signal (wasm://wasm/test_pthread_proxying_canceled_work.wasm-0010c28e:1:21162)
at $pthread_cond_signal (wasm://wasm/test_pthread_proxying_canceled_work.wasm-0010c28e:1:19167)
at $emscripten_proxy_finish (wasm://wasm/test_pthread_proxying_canceled_work.wasm-0010c28e:1:15496)
at $call_then_finish_task (wasm://wasm/test_pthread_proxying_canceled_work.wasm-0010c28e:1:16942)
at $call_with_ctx (wasm://wasm/test_pthread_proxying_canceled_work.wasm-0010c28e:1:16607)
at $em_task_queue_execute (wasm://wasm/test_pthread_proxying_canceled_work.wasm-0010c28e:1:13575)
at $receive_notification (wasm://wasm/test_pthread_proxying_canceled_work.wasm-0010c28e:1:14452)
at $em_task_queue_execute (wasm://wasm/test_pthread_proxying_canceled_work.wasm-0010c28e:1:13575)
at $_emscripten_check_mailbox (wasm://wasm/test_pthread_proxying_canceled_work.wasm-0010c28e:1:28718)
```