make vc_add_test smarter so that special #defines are only used for SSE, AVX, and AVX2
make vc_add_test smarter so that special #defines are only used for SSE, AVX, and AVX2

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