Wrong Doc Identifier span in the parsed source.
## Summary
The Identifier span in the `nested_doc_comment` is wrong
## Steps to reproduce
make a file hello.hs
```{haskell}
module Hello where
{- | `Nothing`
-}
```
generate the parsed source,
```{haskell}
main :: IO ()
main = do
let filePath = "hello.hs"
runGhc (Just libdir) $ do
dflags <- getSessionDynFlags
let dflags' = gopt_set dflags Opt_Haddock
setSessionDynFlags dflags'
target <- guessTarget filePath Nothing Nothing
setTargets [target]
load LoadAllTargets
modSum <- getModSummary $ mkModuleName "Hello"
parsedModule <- parseModule modSum
```
I get the identifier `Nothing` in the doc, which in wrong location.
```
[(L { hello.hs:2:3-9 }
(Unqual
{OccName: Nothing}))]
```
## Expected behavior
parsed source give the correct location of `Nothing` in the doc
```
[(L { hello.hs:2:7-13 }
(Unqual
{OccName: Nothing}))]
```
## Environment
* GHC version used: The Glorious Glasgow Haskell Compilation System, version 9.8.1
Optional:
* Operating System: Macos 14.2.1 (23C71)
* System Architecture: arm64
issue