Consider upgrading Haskell compiler to 9.0.1

[satnam6502]

https://www.haskell.org/ghc/download_ghc_9_0_1.html

[satnam6502]

Will require work e.g.

[ 7 of 62] Compiling Functor          ( Functor.hs, dist/build/Functor.o, dist/build/Functor.dyn_o )

Functor.hs:19:16: error:
    Not in scope: ‘GHC.Base.unsafeCoerce#’
    Perhaps you meant ‘GHC.Base.unsafeChr’ (imported from GHC.Base)
    Module ‘GHC.Base’ does not export ‘unsafeCoerce#’.
   |
19 | unsafeCoerce = GHC.Base.unsafeCoerce#
   |                ^^^^^^^^^^^^^^^^^^^^^^
make: *** [haskell] Error 1

@blaxill

[atondwal]

NB this requires patching the coq haskell extraction plugin, since it still depends on ghc 8, even in the coq master branch (should be a 1-2 line patch, though)