Implement Contiguous and ContiguousU for SmallUnliftedArray

[Qqwy]

These were still missing, and I have need for them 😊.

NOTE: This requires some fixes in primitive-unlifted,
c.f. haskell-primitive/primitive-unlifted#43 and PR haskell-primitive/primitive-unlifted#44

• Contiguous implementation for SmallUnliftedArray
• ContiguousU implementation for SmallUnliftedArray
• Resize helper in Shim for SmallMutableUnliftedArray.
• A temporary implementation of runSmallUnliftedArrayST; also see runSmallUnliftedArrayST is still missing run-st#5 and PR Adds runSmallUnliftedArrayST run-st#6
• Removal of the cabal.project changes that temporarily points to a fork with the fixes to primitive-unlifted applied.

[Qqwy]

I've also committed the cabal.project which makes Cabal look at my primitive-unlifted fork for the time being.

Makes it easy to try out whether these changes work (incl. on CI), but that change should obviously be reverted before this PR is merged.

[andrewthad]

I’ll release A new version of primitive-unlifted to hackage on Monday (that includes the changes you made there), and then I can merge this in.

[Qqwy]

Thank you very much for your swift reply! 💚

[Qqwy]

FYI I pushed a fix for a bug in my earlier implementation for new. I was still relying on undefined as 'default' value there which obviously fails spectacularly when turning all elements strict. The new implementation does exactly the same as the SmallUnliftedArray implementation of new (storing an Any of kind UnliftedType)

[andrewthad]

I've released primitive-unlifted-2.2.0.0. Could you remove the cabal project file and bump the minimum required version of primitive-unlifted in the cabal file? Then I'll review this.

[Qqwy]

@andrewthad done!