meson-winbuild.sh: Remove x-prefixing
There's still some x-prefixing in the parameter handling (--help, --version) of the meson-winbuild.sh. Clean that out.
Also other installer_cross scripts had some x-prefixing. All handled in attached patch.
There's still some x-prefixing in the parameter handling (--help, --version) of the meson-winbuild.sh. Clean that out.