Add nothunks test for parser

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

Cabal/Cabal.cabal

Cabal/src/Distribution/Backpack/UnifyM.hs

Cabal/src/Distribution/PackageDescription.hs

Cabal/src/Distribution/PackageDescription/Check.hs

Cabal/src/Distribution/PackageDescription/FieldGrammar.hs

Cabal/src/Distribution/PackageDescription/Parsec.hs

Cabal/src/Distribution/PackageDescription/PrettyPrint.hs

Cabal/src/Distribution/Simple/Configure.hs

Cabal/src/Distribution/Simple/GHC/Internal.hs

Cabal/src/Distribution/Simple/Program/GHC.hs

Cabal/tests/NoThunks.hs

cabal-install/src/Distribution/Client/List.hs