GHC.Generics: Fix documentation
GHC.Generics: Fix documentation

Fixes #11417.

(cherry picked from commit 91dcc655932b7977c9901d3504bc3d8f0ca8cb6e)

GaloisInc/halvm-ghc,GaloisInc/halvm-ghc,GaloisInc/halvm-ghc,GaloisInc/halvm-ghc,GaloisInc/halvm-ghc,GaloisInc/halvm-ghc,GaloisInc/halvm-ghc