This commit removes stale LLVM include path in D3D8.vcxproj and it
seems that D3D8 does not rely on this include path.

Change-Id: Ieea962ccede9174ef190e1023722f65382cd6ce3
Reviewed-on: https://swiftshader-review.googlesource.com/20468Tested-by: Logan Chien <loganchien@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>