There used to be a button in VS Code's Diff view which controlled whether the entire file, or just the parts that changed, would be shown. It was the accordion-looking icon in the upper right hand corner of this screenshot, two to the left of the ellipses:

I'm no longer seeing this icon (I'm running VS Code version 1.86.1).

What was this feature called? Does it still exist? Is it possible for me to customize the UI of my editor to put the icon back where it was?

Edit: I figured out that it's called "Show/Collapsed Unchanged Regions". I still see it in the toolbar for the inline diff view, but not for the split view. I'm still curious if it's possible to add it back to the toolbar for the split view?