wined3d: Correctly display fog for right-handed projection matrix (try 2)

[Henri Verbeet]

On 18 September 2014 21:57, Joachim Priesner <joachim.priesner at web.de> wrote:
> When using a right-handed projection matrix, z coordinates of vertices may be negative. This is not considered in the code generating the GLSL fog shader. The patch fixes that and adds a test.
>
The patch is likely correct, but the test has room for improvement.
For example, it doesn't currently distinguish between using the
absolute fog coordinate in the vertex shader or doing the same in the
fragment shader. Also, please don't forget about ddraw and d3d8.