Summary:
Post #11019, there have been some new instances of RdrName that are not
located, in particular

```#!hs
data FieldOcc name = FieldOcc { rdrNameFieldOcc  :: RdrName
                              , selectorFieldOcc :: PostRn name name
                              }

data AmbiguousFieldOcc name
  = Unambiguous RdrName (PostRn name name)
  | Ambiguous   RdrName (PostTc name name)
  deriving (Typeable)
```
Add locations to them

Updates haddock submodule to match

Test Plan: ./validate

Reviewers: goldfire, hvr, bgamari, austin

Reviewed By: hvr

Subscribers: hvr, thomie, mpickering

Differential Revision: https://phabricator.haskell.org/D1670

GHC Trac Issues: #11258