message: build: Fix macOS Apple Silicon build with miniupnpc and libnatpmp
  The preferred Homebrew prefix for Apple Silicon is /opt/homebrew.
  Therefore, if we do not use pkg-config to detect packages, we should set
  the CPPFLAGS and LDFLAGS variables for them explicitly.
diff: @@ -707,6 +707,33 @@ case $host in
  if $BREW list --versions qt5 >/dev/null; then
  export PKG_CONFIG_PATH="$($BREW --prefix qt5 2>/dev/null)/lib/pkgconfig:$PKG_CONFIG_PATH"
  fi
  +
  + case $host in
  + *aarch64*)
  + dnl The preferred Homebrew prefix for Apple Silicon is /opt/homebrew.
  + dnl Therefore, as we do not use pkg-config to detect miniupnpc and libnatpmp
  + dnl packages, we should set the CPPFLAGS and LDFLAGS variables for them
  + dnl explicitly.
  + if test "x$use_upnp" != xno && $BREW list --versions miniupnpc >/dev/null; then
  + miniupnpc_prefix=$($BREW --prefix miniupnpc 2>/dev/null)
  + if test "x$suppress_external_warnings" != xno; then
  + CPPFLAGS="$CPPFLAGS -isystem $miniupnpc_prefix/include"
  + else
  + CPPFLAGS="$CPPFLAGS -I$miniupnpc_prefix/include"
  + fi
  + LDFLAGS="$LDFLAGS -L$miniupnpc_prefix/lib"
  + fi
  + if test "x$use_natpmp" != xno && $BREW list --versions libnatpmp >/dev/null; then
  + libnatpmp_prefix=$($BREW --prefix libnatpmp 2>/dev/null)
  + if test "x$suppress_external_warnings" != xno; then
  + CPPFLAGS="$CPPFLAGS -isystem $libnatpmp_prefix/include"
  + else
  + CPPFLAGS="$CPPFLAGS -I$libnatpmp_prefix/include"
  + fi
  + LDFLAGS="$LDFLAGS -L$libnatpmp_prefix/lib"
  + fi
  + ;;
  + esac
  fi
  else
  case $build_os in
  