Fix buildtool/installer on Visual Studio 2017 through 2017.8 (display compiler error) and 2019 preview (download VS2017.9 redist).
Fix buildtool/installer on Visual Studio 2017 through 2017.8 (display compiler error) and 2019 preview (download VS2017.9 redist).

git-svn-id: 763a368b42d23a8c112339c16f7e9c1b0ab7c9a5@883 8a90861a-4eca-46d5-b744-240ff16d0c4d

WilliamFeely/dxgl,WilliamFeely/dxgl,WilliamFeely/dxgl,WilliamFeely/dxgl