clang 17 defaults to C++17, where the 'register' keyword is deprecated and the warning changed to an error. To avoid build errors, compile against C++14 by specifying '-std=c++14' in CXXFLAGS. Signed-off-by: Rebecca Cran <rebecca@quicinc.com> Reviewed-by: Liming Gao <gaoliming@byosoft.com.cn>