macOS Apple Silicon/ARM build errors

[poetaman]

Build command:

./RUNME.sh build -- -DCMAKE_CXX_COMPILER='/opt/homebrew/bin/g++-11' -DCMAKE_CXX_FLAGS='-I/opt/homebrew/Cellar/icu4c/69.1/include'  -DCMAKE_LDFLAGS='-L/opt/homebrew/Cellar/icu4c/69.1/lib -licui18n -licuuc -licudata'

In file included from /Users/reportaman/Downloads/octavia/./src/ob/belle/belle.hh:58,
                 from /Users/reportaman/Downloads/octavia/./src/app/app.hh:58,
                 from /Users/reportaman/Downloads/octavia/src/app/app.cc:46:
/Users/reportaman/Downloads/octavia/./src/ob/belle/signal.hh:133:6: error: 'SIGSTKFLT' was not declared in this scope; did you mean 'SIGSTKSZ'?
  133 |     {SIGSTKFLT, "SIGSTKFLT"},
      |      ^~~~~~~~~
      |      SIGSTKSZ
/Users/reportaman/Downloads/octavia/./src/ob/belle/signal.hh:146:6: error: 'SIGPOLL' was not declared in this scope; did you mean 'SIGKILL'?
  146 |     {SIGPOLL, "SIGPOLL"},
      |      ^~~~~~~
      |      SIGKILL
/Users/reportaman/Downloads/octavia/./src/ob/belle/signal.hh:147:6: error: 'SIGPWR' was not declared in this scope
  147 |     {SIGPWR, "SIGPWR"},
      |      ^~~~~~
/Users/reportaman/Downloads/octavia/./src/ob/belle/signal.hh:149:3: error: no matching function for call to 'std::unordered_map<int, std::__cxx11::basic_string<char> >::unordered_map(<brace-enclosed initializer list>)'
  149 |   };
      |   ^