src/vs/editor/common/languages/modesRegistry.ts/EditorModesRegistry/registerLanguage
class EditorModesRegistry:	public registerLanguage(def: ILanguageExtensionPoint): IDisposable {
		this._languages.push(def);
		this._onDidChangeLanguages.fire(undefined);
		return {
			dispose: () => {
				for (let i = 0, len = this._languages.length; i < len; i++) {
					if (this._languages[i] === def) {
						this._languages.splice(i, 1);
						return;
					}
				}
			}
		};
	}