Cycles: fixes to make CUDA 4.2 work, compiling gave errors in shadows and

other places, was mainly due to instancing not working, but also found
issues in procedural textures.

The problem was with --use_fast_math, this seems to now have way lower
precision for some operations. Disabled this flag and selectively use
fast math functions. Did not find performance regression on GTX 460 after
doing this.

intern/cycles/blender/blender_mesh.cpp

@@ -304,7 +304,6 @@ Mesh *BlenderSync::sync_mesh(BL::Object b_ob, bool object_updated)
 void BlenderSync::sync_mesh_motion(BL::Object b_ob, Mesh *mesh, int motion)
 {
 	/* todo: displacement, subdivision */
-	BL::ID b_ob_data = b_ob.data();
 	size_t size = mesh->verts.size();
 
 	/* skip objects without deforming modifiers. this is not a totally reliable,