Define minimal version of target framework

HasSSE.csproj

  <Choose>
    <When Condition=" $(TargetFrameworkVersion.Replace('v', '')) &gt;= 4.6 ">
      <ItemGroup>
        <Reference Include="System.Numerics" />
        <Reference Include="System.Numerics.Vectors, Version=4.1.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL">
          <HintPath>..\packages\System.Numerics.Vectors.4.1.0\lib\net46\System.Numerics.Vectors.dll</HintPath>
          <Private>True</Private>
        </Reference>
      </ItemGroup>
      <PropertyGroup>
        <DefineConstants>SIMD</DefineConstants>
      </PropertyGroup>
    </When>
  </Choose>