Fix 404 link to GHC docs for the UNPACK pragma

Release 0.8.9.2

-Wnoncanonical-monadfail-instances is deprecated: fail is no longer a…

Future-proof against potential Prelude.foldl'

Drop efficiency wording from README

Added comments for Float and Double instances

Mark many in Alternative instance as INLINEABLE

Update supported compiler versions in CI and the cabal file

Test CI

I have given up on tests and benchmarks for the moment due to cyclic
package dependencies.

Add GitHub Actions-based CI

Since many is recursive ghc will never inline it. Even if we mark as INLINE.
However ghc will complain if we compile with core lint enabled.

So we just mark it as INLINEABLE instead.

Adapt to changes in TypeRep complete patterns

GHC merge request !963 improved warnings in the presence of
COMPLETE annotations. This allows the removal of the Fun pattern
from the complete set.

This patch accounts for the resulting changes in pattern match warnings.

Bump version to 0.8.9.0

Changes for GHC 9.2.1

Otherwise GHC 9.2 will compile the package as GHC2021, which will break
due to a Safe Haskell error. See GHC #19631.

Bring in changes GHC 9.2 is using

Remove instance for Data.Semigroup.Option for GHC >= 9.2

Use unsafe shifts from base rather than hand-rolling

See
https://hackage.haskell.org/package/base-4.5.0.0/docs/Data-Bits.html#v:unsafeShiftL.
in binary's minimum supportedbase version.

Beyond reducing duplicated code, this will avoid CPP in dealing with the
changing primop situation for GHC 9.2.