Repro steps:

1. Open SceneController scene from attached project.
2. Make sure profiler is running and visible
3. Press Play
4. Press Right arrow button on keyboard to switch to next scene.
5. Observe spike in profiler.
6. Select spike and observe GC allocation (around 1.2 MB)
7. Compare with 5.5, the same spike is only a few kb.

Expected outcome: GC allocation to not be that large.

Notes:
- Press "R" to reload the scene and view the spike again.
- Happens with all large scenes which have many particle systems
- Did not detect noticeable overhead in scenes with fewer (5-10) systems.
- Doesn't occur in 5.5.0p3, happens in 5.6