koalaman
Drop support for some really old GHC versions
https://github.com/koalaman/shellcheck/blob/3946cbd4a0b477700172c04be7baa3f43777bc99/ShellCheck.cabal#L44-L66
These lower bounds are really, really old. GHC 7.10.3 is from 2015. Can we drop support for some older versions? If we want to be conservative, I think a good new lower bound would be GHC 8.2, since that's what RHEL (EPEL) 8 ships, and to my knowledge, there are no supported versions of any mainstream distros that ship anything older.
Being old is not really a bad thing. Most of the shell definitions are very old. As long as the lower bounds does not hamper development into upper bounds the make no harm IMHO.
What led to me asking about this is that there's a bunch of places in the code that clumsily create a Map k () just to pass to Map.difference. I wanted to change them to create a Set k and use Map.withoutKeys instead, but that's new to containers 0.5.8 (released 8 years ago), and our lower bound is 0.5.6.
Also, a while ago I found some code that was basically reimplementing fromRight, so I tried to replace it with calls to it instead, but that's new to GHC 8.2 (released 7 years ago).