src/vs/editor/contrib/hover/hover.ts/ModesHoverController/_onKeyDown
class ModesHoverController:	private _onKeyDown(e: IKeyboardEvent): void {
		if (e.keyCode !== KeyCode.Ctrl && e.keyCode !== KeyCode.Alt && e.keyCode !== KeyCode.Meta && e.keyCode !== KeyCode.Shift) {
			// Do not hide hover when a modifier key is pressed
			this._hideWidgets();
		}
	}