let -mXXX flags to to Vc_ARCHITECTURE_FLAGS instead of the global CMAKE_CXX_FLAGS
let -mXXX flags to to Vc_ARCHITECTURE_FLAGS instead of the global CMAKE_CXX_FLAGS

VcDevel/Vc,VcDevel/Vc,VcDevel/Vc,chr-engwer/Vc,VcDevel/Vc,chr-engwer/Vc,chr-engwer/Vc