LLVM roller failing with `undefined symbol: __gxx_wasm_personality_v0`

[sbc100]

Seems to be caused by llvm/llvm-project#209282 :

======================================================================
FAIL: test_embind_val_coro_catch_cpp_exception_wasm_eh (test_core.core0.test_embind_val_coro_catch_cpp_exception_wasm_eh)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/usr/local/google/home/sbc/dev/wasm/emscripten/test/common.py", line 1272, in run_process
    rtn = utils.run_process(cmd, check=check, **kwargs)
  File "/usr/local/google/home/sbc/dev/wasm/emscripten/tools/utils.py", line 45, in run_process
    ret = subprocess.run(cmd, check=check, input=input, *args, **kw)
  File "/usr/lib/python3.13/subprocess.py", line 577, in run
    raise CalledProcessError(retcode, process.args,
                             output=stdout, stderr=stderr)
subprocess.CalledProcessError: Command '['/usr/local/google/home/sbc/dev/wasm/emscripten/em++', '/usr/local/google/home/sbc/dev/wasm/emscripten/test/embind/test_val_coro.cpp', '-o', 'test_val_coro.js', '-sNO_DEFAULT_TO_CXX', '-sEXCEPTION_STACK_TRACES', '-Wclosure', '-Werror', '-Wno-limited-postlink-optimizations', '-O0', '-std=c++20', '--bind', '--pre-js=pre.js', '-fwasm-exceptions', '-sINCOMING_MODULE_JS_API=onRuntimeInitialized', '--no-entry']' returned non-zero exit status 1.

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/local/google/home/sbc/dev/wasm/emscripten/test/common.py", line 403, in resulting_test
    return func(self, *args)
  File "/usr/local/google/home/sbc/dev/wasm/emscripten/test/test_core.py", line 7782, in test_embind_val_coro_catch_cpp_exception
    self.do_runf('embind/test_val_coro.cpp', 'successfully caught!\n')
    ~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/google/home/sbc/dev/wasm/emscripten/test/common.py", line 1452, in do_runf
    return self._build_and_run(filename, *args, **kwargs)
           ~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/google/home/sbc/dev/wasm/emscripten/test/common.py", line 1481, in _build_and_run
    js_file = self.build(filename, **kwargs)
  File "/usr/local/google/home/sbc/dev/wasm/emscripten/test/common.py", line 969, in build
    self.run_process(cmd, stderr=self.stderr_redirect if not DEBUG else None)
    ~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/google/home/sbc/dev/wasm/emscripten/test/common.py", line 1277, in run_process
    self.fail(f'subprocess exited with non-zero return code({e.returncode}): `{shlex.join(cmd)}`')
    ~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AssertionError: subprocess exited with non-zero return code(1): `/usr/local/google/home/sbc/dev/wasm/emscripten/em++ /usr/local/google/home/sbc/dev/wasm/emscripten/test/embind/test_val_coro.cpp -o test_val_coro.js -sNO_DEFAULT_TO_CXX -sEXCEPTION_STACK_TRACES -Wclosure -Werror -Wno-limited-postlink-optimizations -O0 -std=c++20 --bind --pre-js=pre.js -fwasm-exceptions -sINCOMING_MODULE_JS_API=onRuntimeInitialized --no-entry`

Stdout:
wasm-ld: error: /tmp/emscripten_temp_qpw26sls/test_val_coro.o: undefined symbol: __gxx_wasm_personality_v0
wasm-ld: error: /tmp/emscripten_temp_qpw26sls/test_val_coro.o: undefined symbol: __gxx_wasm_personality_v0
wasm-ld: error: /tmp/emscripten_temp_qpw26sls/test_val_coro.o: undefined symbol: __gxx_wasm_personality_v0
wasm-ld: error: /tmp/emscripten_temp_qpw26sls/test_val_coro.o: undefined symbol: __gxx_wasm_personality_v0
em++: error: '/usr/local/google/home/sbc/dev/wasm/llvm-build/bin/wasm-ld -o test_val_coro.wasm /tmp/tmpt6t28rg5libemscripten_js_symbols.so -Bstatic --strip-debug --export=emscripten_stack_get_end --export=emscripten_stack_get_free --export=emscripten_stack_get_base --export=emscripten_stack_get_current --export=emscripten_stack_init --export=_emscripten_stack_alloc --export=__getTypeName --export=__trap --export=__wasm_call_ctors --export-if-defined=__start_em_asm --export-if-defined=__stop_em_asm --export-if-defined=__start_em_lib_deps --export-if-defined=__stop_em_lib_deps --export-if-defined=__start_em_js --export-if-defined=__stop_em_js --export-if-defined=fflush --export-table -z stack-size=65536 --no-growable-memory --initial-heap=16777216 --no-entry --stack-first --table-base=1 /tmp/emscripten_temp_qpw26sls/test_val_coro.o -lembind-rtti -L/usr/local/google/home/sbc/dev/wasm/emscripten/cache/sysroot/lib/wasm32-emscripten -L/usr/local/google/home/sbc/dev/wasm/emscripten/src/lib -lGL-getprocaddr -lal -lhtml5 -lstubs-debug -lnoexit -lc-debug -ldlmalloc-debug -lclang_rt.builtins-legacysjlj -lc++-debug-legacyexcept -lc++abi-debug-legacyexcept -lunwind-legacyexcept -lsockets -mllvm -combiner-global-alias-analysis=false -mllvm -wasm-enable-sjlj -mllvm -wasm-use-legacy-eh -mllvm -disable-lsr -mllvm -wasm-enable-eh -mllvm -exception-model=wasm' failed (returned 1)

None

----------------------------------------------------------------------
Ran 1 test in 2.518s

FAILED (failures=1)

[sbc100]

I guess we need to somehow update our libunwind at the same time as bumping the llvm version?

Could we temporarily support both old and new llvm versions with our libunwind?