Otherwise file browsers do not recognize the Blender executable. This is
already done for official releases.
We leave it off for non-portable builds, since that's how Linux distribution
packages will typically build Blender and we can continue to follow the OS
default there. Using a file browser to launch executables from e.g. /usr/bin
would be rare as wel.
Differential Revision: https://developer.blender.org/D7363