test failures on aarm64

• test/regress/wasm2c-ehv3-setjmp-volatile.txt
  expected error code 0, got 250.
  STDERR MISMATCH:
  --- expected
  +++ actual
  @@ -0,0 +1 @@
  +sigaltstack failed: Invalid argument

• test/wasm2c/spec/exception-handling/throw.txt
  expected error code 0, got 250.
  STDERR MISMATCH:
  --- expected
  +++ actual
  @@ -0,0 +1 @@
  +sigaltstack failed: Invalid argument

[+1864|-2|%100] (103.63s) test/wasm2c/spec/simd_const.txt
**** FAILED ******************************************************************

• test/regress/wasm2c-ehv3-setjmp-volatile.txt
  /usr/local/bin/python3 /wabt/test/run-spec-wasm2c.py out/test/regress/wasm2c-ehv3-setjmp-volatile.txt --bindir=/wabt/bin --no-error-cmdline -o out/test/regress/wasm2c-ehv3-setjmp-volatile --enable-exceptions
• test/wasm2c/spec/exception-handling/throw.txt
  /usr/local/bin/python3 /wabt/test/run-spec-wasm2c.py out/test/wasm2c/spec/exception-handling/throw.wast --bindir=/wabt/bin --no-error-cmdline -o out/test/wasm2c/spec/exception-handling/throw --enable-exceptions

Start by running the two listed cases, test/regress/wasm2c-ehv3-setjmp-volatile.txt and test/wasm2c/spec/exception-handling/throw.txt, with test/run-spec-wasm2c.py on aarm64. Compare the expected and actual stderr, especially the sigaltstack failure; done means these cases pass without the reported error-code or stderr mismatches.