To reproduce:

1. Open the project, attached by tester (particlesComponentBug.zip)
2. Open "testScene" scene if not already open
3. Select Particle System game object in the Hierarchy
4. Open script.cs and change Update to Start
5. Return to Unity, make sure the Particle System game object is selected and Inspector window is open
6. After compiling, observe the Particle System component

Expected: Unity compiles code normally without breaking the Particle System component
Actual: Particle System component becomes broken if it is open in the inspector while Unity compiles scripts

Reproduced in 2017.1.0b2, 2017.1.0b3, 2017.1.0b4
Did not reproduce in 2017.1.0b1
Regression introduced in 2017.1.0b2