Incorrect assumptions about wine64

[KenSharp]

With WINE=wine-10.0, winetricks gives WINE64=wine64-10.0.
This fails.

The comment in the code acknowledges a potentional issue:
# Probably need fancier handling/checking

WINE_MULTI=wine-10.0 is correct, but it doesn't seem to be used when running, for example, winetricks arial which calls w_try_regedit():

w_try_regedit32()
{
    # on windows, doesn't work without cmd /c
    case "${W_PLATFORM}" in
        windows_cmd|wine_cmd) cmdc="cmd /c";;
        *) unset cmdc ;;
    esac

    if [ "${W_ARCH}" = "win64" ]; then
        # shellcheck disable=SC2086
        w_try "${WINE}" ${cmdc} "${W_SYSTEM32_DLLS_WIN}\\regedit.exe" ${W_OPT_UNATTENDED:+/S} "$@"
    else
        # shellcheck disable=SC2086
        w_try "${WINE}" ${cmdc} "C:\\windows\\regedit.exe" ${W_OPT_UNATTENDED:+/S} "$@"
    fi
}

w_try_regedit64()
{
    # on windows, doesn't work without cmd /c
    case "${W_PLATFORM}" in
        windows_cmd|wine_cmd) cmdc="cmd /c";;
        *) unset cmdc ;;
    esac

    # shellcheck disable=SC2086
    w_try "${WINE64}" ${cmdc} "C:\\windows\\regedit.exe" ${W_OPT_UNATTENDED:+/S} "$@"
}

Workaround is WINE64="${WINE}" in this case, but that won't always work, of course.