Singletons can have keywords for a name
Created by: kisiel090
Godot version: 3.0 stable win64
Issue description: In the autoload tab, in project settings you can set singleton name to, for example, "const". You will be unable to use this singleton in gdscript, as editor assumes you are using a keyword. MVP.zip
Steps to reproduce: add a singleton with name that is a reserved keyword in gdscript