Fix T37003, Fix T37859: smoke modifier taking deforming modifiers into account

in some cases.

The smoke modifier now ignores the modifier evaluation for generated texture
coordinates, which would previously cause the undeformed mesh to be cached for
flow objects. Dynamic paint has a similar exception, and other physics systems
avoid it by not being a constructive modifier.

source/blender/modifiers/intern/MOD_smoke.c

@@ -101,10 +101,13 @@ static CustomDataMask requiredDataMask(Object *UNUSED(ob), ModifierData *md)
 
 static DerivedMesh *applyModifier(ModifierData *md, Object *ob, 
                                   DerivedMesh *dm,
-                                  ModifierApplyFlag UNUSED(flag))
+                                  ModifierApplyFlag flag)
 {
 	SmokeModifierData *smd = (SmokeModifierData *) md;
 
+	if(flag & MOD_APPLY_ORCO)
+		return dm;
+
 	return smokeModifier_do(smd, md->scene, ob, dm);
 }