message: Bounds check all cursors just before running any action
  In some sense this is a bit blunt, and it may conceal some real issues, but I think that's fine, at least for now.
  Fixes fixes fixes
  Refs
diff: @@ -700,6 +700,16 @@ export class ModeHandler implements vscode.Disposable {
  );
  }
  + // Make sure all cursors are within the document's bounds before running any action
  + // It's not 100% clear to me that this is the correct place to do this, but it should solve a lot of issues
  + this.vimState.cursors = this.vimState.cursors.map(
  + (c) =>
  + new Range(
  + this.vimState.document.validatePosition(c.start),
  + this.vimState.document.validatePosition(c.stop)
  + )
  + );
  +
  if (action instanceof BaseMovement) {
  recordedState = await this.executeMovement(action);
  ranAction = true;
  