Binutils before 2.21 does not support AVX2

Thanks to Pere Mato Vila <Pere.Mato@cern.ch> for the patch.

Fixes: gh-104
Signed-off-by: Matthias Kretz <kretz@kde.org>

cmake/VcMacros.cmake

@@ -162,8 +162,9 @@ macro(vc_check_assembler)
          set(Vc_XOP_INTRINSICS_BROKEN true)
          set(Vc_FMA4_INTRINSICS_BROKEN true)
       elseif(_as_version VERSION_LESS "2.21.0")
-         UserWarning("Your binutils is too old (${_as_version}) for XOP instructions. They will therefore not be provided in libVc.")
+         UserWarning("Your binutils is too old (${_as_version}) for XOP and AVX2 instructions. They will therefore not be provided in libVc.")
          set(Vc_XOP_INTRINSICS_BROKEN true)
+         set(Vc_AVX2_INTRINSICS_BROKEN true)
       endif()
    endif()
 endmacro()