On the Merge Request "Changes" tab, make the "Show all unchanged lines" link text indicate the specific number of lines that it will show
Proposal
When I'm reviewing a merge request, I often like to see some additional context, and I need to choose between clicking "Show 20 lines" several times (in order to reveal the beginning and end of the function I'm looking at), or clicking "Show all unchanged lines" which will reveal an unspecified number of lines. In large source files with thousands of lines, if I click "Show all unchanged lines" then the page will get much longer, which can make it difficult to find the actual change again (among the thousands of unchanged lines that are now visible).
If those links instead said (for example) "Show all 78 unchanged lines" or "Show all 5,678 unchanged lines", it would make that decision easier — I could click the "Show all 78 unchanged lines" without worrying about losing my place, and I could avoid clicking "Show all 5,678 unchanged lines" unless I really really wanted to see all of that.