Steps to reproduce:

1. Open Unity;
2. Open attached project and 'main.unity' scene;

3. Notice that there is a plane with 'Rock Spawner' gameobject, which spawns rocks with GPU instancing and Reflection Probe zone, covering some of the spawner zone;
4. Enter Play mode;
5. Select 'Reflection Probe' gameobject;
6. Enable 'Reflection Probe' gameobject in the Inspector;
7. Observe Scene and Game views.

Actual result:
Instanced objects that get into Reflection Probe zone are flickering, that creates problems of using GPU instancing in combination with reflection probes.
See attached gif video and and actual.gif file.

Expected result:
Instanced objects should not flicker while being in the Reflection probe zone (see attached expected.gif file).

Notes:
- Reproduced in 5.4.0b3 (trunk) on Windows 10 (DX11) and on OSX 10.11.2 (graphics/instancing/dev/gles3 branch) in GLCore mode;
- Workaround is either not to use Instanced Shader (that would break instancing) or turn off reflection probe.