Fix rendering issue on letters on Kengo/burnout 3/...
Default algo will execute the alpha test in 2 passes. However due to blending
you can't handle accurately the color.
Fortunately for us, the rendering uses an always pass depth test so you
can execute first all the color rendering (which doesn't depends on the alpha test)
And then the depth part which depends on the alpha test.
Gregory Hainaut
8b94320524