Made Windows files work for Windows clang.
Verified on Linux and Windows Visual Studio
compiler to make sure nothing was broken.

Change-Id: I82815491579cdfca602660279f6831c8820249f6
Reviewed-on: https://swiftshader-review.googlesource.com/7052Tested-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Corentin Wallez <cwallez@google.com>
Reviewed-by: Alexis Hétu <sugoi@google.com>