Fix gl_FrontFacing to take GL_FRONT_FACE into account.

Bug swiftshader:113

Change-Id: Ia1cbcdbb396eaabaa79e4c8651d7c025f73d028a
Reviewed-on: https://swiftshader-review.googlesource.com/20068
Reviewed-by: Alexis Hétu <sugoi@google.com>
Tested-by: Nicolas Capens <nicolascapens@google.com>
diff --git a/src/OpenGL/libGLES_CM/Device.cpp b/src/OpenGL/libGLES_CM/Device.cpp
index d1c3a04..4df82e5 100644
--- a/src/OpenGL/libGLES_CM/Device.cpp
+++ b/src/OpenGL/libGLES_CM/Device.cpp
@@ -46,7 +46,7 @@
 		setAlphaTestEnable(false);
 		setSourceBlendFactor(BLEND_ONE);
 		setDestBlendFactor(BLEND_ZERO);
-		setCullMode(CULL_COUNTERCLOCKWISE);
+		setCullMode(CULL_COUNTERCLOCKWISE, true);
 		setDepthCompare(DEPTH_LESSEQUAL);
 		setAlphaReference(0.0f);
 		setAlphaCompare(ALPHA_ALWAYS);