[scss] Incorrect selector specificity in hover tooltip

<!-- Please search existing issues to avoid creating duplicates. --> <!-- Also please test using the latest insiders build to make sure your issue has not already been fixed: https://code.visualstudio.com/insiders/ --> <!-- Use Help > Report Issue to prefill these. --> - VSCode Version: 1.33.1 - OS Version: Windows 10 Steps to Reproduce: 1. Type the code like  2. Move the mouse over `&__b`  The selector specificity is displayed as (0, 0, 0) instead of the correct (0, 1, 0), it being a class selector. <!-- Launch with `code --disable-extensions` to check. --> Does this issue occur when all extensions are disabled?: Yes/No Yes.