This change of SmmCpuExceptionHandlerLib adds support for StandaloneMm components to allow x64 StandaloneMm environment setting up exception handlers. Cc: Eric Dong <eric.dong@intel.com> Cc: Ray Ni <ray.ni@intel.com> Cc: Laszlo Ersek <lersek@redhat.com> Cc: Rahul Kumar <rahul1.kumar@intel.com> Signed-off-by: Kun Qin <kun.q@outlook.com> Reviewed-by: Laszlo Ersek <lersek@redhat.com> Reviewed-by: Ray Ni <ray.ni@intel.com>