How to reproduce:
1. Open attached project "SRPJobs-20192.zip" and scene "SRP0102_AssetSettings"
2. In the Hierarchy window, select all the "Particle System" objects
3. In the Inspector window, change "Particle System" -> "Max Particles" to 5000
4. In the Inspector window, change "Particle System" -> "Emission" -> "Rate over Time" so that the Editor runs at about 5-10 fps (the "Rate over Time" will depend on the computer speed)
5. Open "Window" -> "Analysis" -> "Profiler"
6. Enter Play mode
7. Expand the "Profiler" -> "Render Thread" as much as possible
8. Observe "Profiler" -> "Render Thread" blue regions ()
9. After 1 minute of running in Play mode close the Editor

Expected result: the Editor closes
Actual result: the Editor hangs and never closes

Reproducible with: 2018.3.13f1, 2019.1.0f2, 2019.2.0a12