When keywords are included from "X" language, the syntax highlighting of the "X" language will not be loaded:
* The "IncludeRules" rule, from the "X" language, doesn't work.
* It isn't possible to open files of the "X" language while the text editor is open.
<context name="Normal" attribute="Normal Text" lineEndContext="#stay">
<IncludeRules context="##C" />
Also, this bug can be noticed when opening a SCSS file and then a CSS file; the CSS file is not loaded, since SCSS includes CSS keywords.
This happens, because when, in `DefinitionData`, if `keywordIsLoaded` is `true`, the `loadHighlighting(...)` method is returned and doesn't read the content of the `<highlighting>` tag.