workaround missing feature checks in ICC intrin headers
workaround missing feature checks in ICC intrin headers

ICC with recent libstdc++ includes ia32intrin.h which declares all intrinsics, even if only SSE2 is selected

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