Steps to repro:

1. Create new project;
2. Open File context menu;
3. Observe Build&Run buttons number.

Expected result:
There is only one Build&Run button in the context menu.

Actual result:
Unneeded second Build&Run button is shown under Exit button. See attached screenshot.

Regression introduced in Unity 2017.3.0a2.

Notes:
- Reproducible in 2017.3.0a2;
- Not reproducible in 2017.3.0a1, 2017.2.0b5, 2017.1.0p2;
- Reproducible only on Windows 10; not reproducible on OSX 10.12.5;
- Pressing that button throws exception.