This change requires a series of related changes, which must all land
at the same time, otherwise all the EPA tests break.

* Use the current Anchor end as prior end

  Use the original anchor location end as the source of truth for
  calculating print deltas.

  This allows original spacing to apply in most cases, only changed
  AST items need initial delta positions.

* Add DArrow to TrailingAnn

* EPA Introduce HasTrailing in ExactPrint

   Use [TrailingAnn] in enterAnn and remove it from
   ExactPrint (LocatedN RdrName)

* In HsDo, put TrailingAnns at top of LastStmt

* EPA: do not convert comments to deltas when balancing.

* EPA: deal with fallout from getMonoBind

* EPA fix captureLineSpacing

* EPA print any comments in the span before exiting it

* EPA: Add comments to AnchorOperation

* EPA: remove AnnEofComment, it is no longer used

Updates Haddock submodule