Rewinding a system with a subemitter using trails causes the trails to glitch out.

Repro steps:
1. Open Scene1 from the attached project
2. Select the Explosion particle system in the hierarchy and simulate it
3. Pause the system around the 1 second mark and rewind it slowly back to about 0.17 seconds
4. Observe visual artefacts. Zoom out in the scene view to make them even more prominent.

Notes:
- not a regression, happens in 5.5.2p4
- seems like trails have to be coming from a sub emitter; could not repro otherwise