Remove global refrences from common code.

Bug Fix: Previously vertex shaders and geometery shaders didn't track
         antialaising state in their UIDs, which could cause AA bugs
	 on directx.

Source/Core/VideoCommon/GeometryShaderGen.h

@@ -23,6 +23,8 @@ struct geometry_shader_uid_data
   u32 pixel_lighting : 1;
   u32 primitive_type : 2;
   u32 wireframe : 1;
+  u32 msaa : 1;
+  u32 ssaa : 1;
 };
 
 #pragma pack()