Trees That Grow refactor for `ConPat` and `CoPat`

- `ConPat{In,Out}` -> `ConPat`

- `CoPat` -> `XPat (CoPat ..)`

Note that `GHC.HS.*` still uses `HsWrap`, but only when `p ~ GhcTc`.
After this change, moving the type family instances out of `GHC.HS.*` is
sufficient to break the cycle.

Add XCollectPat class to decide how binders are collected from XXPat based on the pass.

Previously we did this with IsPass, but that doesn't work for Haddock's
DocNameI, and the constraint doesn't express what actual distinction is being
made. Perhaps a class for collecting binders more generally is in order, but we
haven't attempted this yet.

Pure refactor of code around ConPat

 - InPat/OutPat synonyms removed

 - rename several identifiers

 - redundant constraints removed

 - move extension field in ConPat to be first

 - make ConPat use record syntax more consistently

Fix T6145 (ConPatIn became ConPat)

Add comments from SPJ.

Add comment about haddock's use of CollectPass.

Updates haddock submodule.

1 files changed, 7 insertions, 3 deletions

diff --git a/compiler/GHC/Tc/Deriv/Generate.hs b/compiler/GHC/Tc/Deriv/Generate.hs
index 5156bb0aa1..ad103ca7c8 100644
--- a/compiler/GHC/Tc/Deriv/Generate.hs
+++ b/compiler/GHC/Tc/Deriv/Generate.hs
@@ -532,9 +532,13 @@ unliftedCompare lt_op eq_op a_expr b_expr lt eq gt
 
 nlConWildPat :: DataCon -> LPat GhcPs
 -- The pattern (K {})
-nlConWildPat con = noLoc (ConPatIn (noLoc (getRdrName con))
-                                   (RecCon (HsRecFields { rec_flds = []
-                                                        , rec_dotdot = Nothing })))
+nlConWildPat con = noLoc $ ConPat
+  { pat_con_ext = noExtField
+  , pat_con = noLoc $ getRdrName con
+  , pat_args = RecCon $ HsRecFields
+      { rec_flds = []
+      , rec_dotdot = Nothing }
+  }
 
 {-
 ************************************************************************