Use newer -W and -Wno- warning flags

Cabal-QuickCheck/src/Test/QuickCheck/Instances/Cabal.hs

Cabal-hooks/Cabal-hooks.cabal

Cabal-syntax/Cabal-syntax.cabal

...ntax/src/Distribution/PackageDescription/Configuration.hs

Cabal-tests/tests/HackageTests.hs

Cabal-tests/tests/Test/Laws.hs

Cabal-tests/tests/UnitTests/Distribution/CabalSpecVersion.hs

Cabal-tests/tests/UnitTests/Distribution/Compat/Graph.hs

Cabal-tests/tests/UnitTests/Distribution/Described.hs

Cabal-tests/tests/UnitTests/Distribution/SPDX.hs

Cabal-tests/tests/UnitTests/Distribution/System.hs

...UnitTests/Distribution/Types/GenericPackageDescription.hs

Cabal-tests/tests/UnitTests/Distribution/Utils/Generic.hs

Cabal-tests/tests/UnitTests/Distribution/Utils/NubList.hs

Cabal-tests/tests/UnitTests/Distribution/Version.hs

Cabal-tree-diff/src/Data/TreeDiff/Instances/Cabal.hs

Cabal-tree-diff/src/Data/TreeDiff/Instances/CabalLanguage.hs

Cabal-tree-diff/src/Data/TreeDiff/Instances/CabalSPDX.hs

Cabal-tree-diff/src/Data/TreeDiff/Instances/CabalVersion.hs

Cabal/Cabal.cabal