Could you explain what you mean by "marked as executable"? I'm pretty sure this is something I'm not familiar with, and since diff doesn't show anything, it's hard to review.

All files have an "execute bit" stored as part of their metadata, which indicates whether the file can be executed on its own (e.g. as ./foo.js rather than node foo.js). Since lib/linter.js previously had its execute bit set, it was possible to run lib/linter.js in a shell and have it be interpreted as a bash script. However, this was not useful for anything and would generally result in a syntax error. The bit was probably not set intentionally.

I don't know of any existing plugins. (I found these files with fselect.) Maybe that could be something added to eslint-plugin-node.