In the following

  data FieldOcc pass = FieldOcc { extFieldOcc     :: XFieldOcc pass
                                , rdrNameFieldOcc :: Located RdrName
                                   -- ^ See Note [Located RdrNames] in HsExpr
                                }

    | XFieldOcc
        (XXFieldOcc pass)

we are using XFieldOcc for both the extFieldOcc type and the extra constructor.

The first one should be XCFieldOcc

Updates haddock submodule
closes #15386