abbr --erase should erase old uvars

[faho]

Discussed in #9467

^{Originally posted by nap2001 January 13, 2023}

Since release 3.6.0's enhancements to abbreviations, I need to rethink/redesign/cleanup my abbreviations. How do I get rid of my pre-3.6.0 universal abbreviations? I've tried "abbr -e" but that only deletes in the current shell and new shells still have the deleted old abbreviation. I have 105 universal abbreviations and think I should just start over given changes in 3.6.0.

That abbr -e should have worked. It's the obvious choice - everything else requires dropping down to the variables, which have scary _fish_abbr_ names.