Comments fragment identifier has disappeared

Problem/Motivation

On node teasers, the Comment module adds a few links :

1. "X comments" which leads to /node/NID#comments but the anchor does not exist in the page ;
2. "New" (if there are new comments the user didn't read) which leads to /node/NID#new that only works if you only have one comment field => See #2969255: Comments + History "new" link only works with one comment field →

Steps to reproduce #1

1. Install Drupal standard
2. Create an article with a huge body
3. Add a comment to this article
4. Go to the front page and click on the "1 comment" link of your article

Expected: you are redirected to the node page and the browser shows the comment
Current: you are redirected to the node page but the browser show the top of the page

Proposed resolution

Add the field name to the anchor so it becomes "comments--[field-name]".
Add the "comments--[field-name]" id on the comments wrapper.

Remaining tasks

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User interface changes

None.

API changes

None.

Data model changes

None.