Fixup switch warning; Use count_limit2; Benchmark ghostrider before flex

Fix spam during compilation: ``` /usr/src/xmrig/src/backend/cpu/platform/BasicCpuInfo.cpp: In member function ‘virtual xmrig::CpuThreads xmrig::BasicCpuInfo::threads(const xmrig::Algorithm&, uint32_t) const’: /usr/src/xmrig/src/backend/cpu/platform/BasicCpuInfo.cpp:393:12: warning: enumeration value ‘INVALID’ not handled in switch [-Wswitch] 393 | switch (algorithm.id()) { | ^ /usr/src/xmrig/src/backend/cpu/platform/BasicCpuInfo.cpp:393:12: warning: enumeration value ‘CN_0’ not handled in switch [-Wswitch] /usr/src/xmrig/src/backend/cpu/platform/BasicCpuInfo.cpp:393:12: warning: enumeration value ‘CN_1’ not handled in switch [-Wswitch] /usr/src/xmrig/src/backend/cpu/platform/BasicCpuInfo.cpp:393:12: warning: enumeration value ‘CN_2’ not handled in switch [-Wswitch] /usr/src/xmrig/src/backend/cpu/platform/BasicCpuInfo.cpp:393:12: warning: enumeration value ‘CN_R’ not handled in switch [-Wswitch] /usr/src/xmrig/src/backend/cpu/platform/BasicCpuInfo.cpp:393:12: warning: enumeration value ‘CN_FAST’ not handled in switch [-Wswitch] ... ``` Also use `count_limit2` like everything else does, and do ghostrider before flex in benchmarking (in case the subalgo optimization test/selections matter).