Add support for GHC 9.10, remove support for GHC 9.4

[tfausak]

No description provided.

[tfausak]

I'm getting a warning here with GHC 9.10.1:

imp/source/library/Imp.hs

Lines 83 to 87 in 9fa7f61

	imports =
	Set.fromList
	. fmap (ImportDecl.toModuleName . Plugin.unLoc)
	. Hs.hsmodImports
	$ Plugin.unLoc lHsModule

The warning is:

source/library/Imp.hs:86:13: warning: [GHC-17335] [-Wincomplete-record-selectors]
    The application of the record field ‘Hs.hsmodImports’ may fail for the following constructors: Hs.XModule
   |
86 |           . Hs.hsmodImports
   |             ^^^^^^^^^^^^^^^

I think that's incorrect because the HsModule type effectively only has one constructor for the GhcPs pass: https://hackage.haskell.org/package/ghc-9.10.1/docs/GHC-Hs.html#t:HsModule

And indeed trying to avoid the warning just generates a different warning:

source/library/Imp.hs:88:9: warning: [GHC-53633] [-Woverlapping-patterns]
    Pattern match is redundant
    In a case alternative: Hs.XModule {} -> ...
   |
88 |         Hs.XModule {} -> Set.empty
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^

I think this is a GHC bug.

[tfausak]

I worked around the problem by using positional arguments instead of record selectors. I also created an upstream issue: https://gitlab.haskell.org/ghc/ghc/-/issues/24824

[tfausak]

This page is very useful and I always have trouble finding it:
https://gitlab.haskell.org/ghc/ghc/-/wikis/commentary/libraries/version-history