case over signum of Integer is incorrect in GHC 9.2
Summary
case over signum of Integer returns an incorrect result.
Steps to reproduce
GHCi, version 9.2.0.20210331: https://www.haskell.org/ghc/ :? for help
ghci> signum (-1 :: Integer)
-1
ghci> case signum (-1 :: Integer) of 1 -> "FOO"; -1 -> "OK"; 0 -> "BAR"; _ -> "FAIL"
"FAIL"Expected behavior
I would expect the second line to return "OK".
Environment
- GHC version used: 9.2.0.20210331