Introduce Concrete# for representation polymorphism checks

PHASE 1: we never rewrite Concrete# evidence.

This patch migrates all the representation polymorphism checks to
the typechecker, using a new constraint form

  Concrete# :: forall k. k -> TupleRep '[]

Whenever a type `ty` must be representation-polymorphic
(e.g. it is the type of an argument to a function), we emit a new
`Concrete# ty` Wanted constraint. If this constraint goes
unsolved, we report a representation-polymorphism error to the user.
The 'FRROrigin' datatype keeps track of the context of the
representation-polymorphism check, for more informative error messages.

This paves the way for further improvements, such as
allowing type families in RuntimeReps and improving the soundness
of typed Template Haskell. This is left as future work (PHASE 2).

fixes #17907 #20277 #20330 #20423 #20426

updates haddock submodule

-------------------------
Metric Decrease:
    T5642
-------------------------

2 files changed, 9 insertions, 9 deletions

diff --git a/compiler/GHC/Iface/Ext/Ast.hs b/compiler/GHC/Iface/Ext/Ast.hs
index 58047e531f..fbeaa8ca3a 100644
--- a/compiler/GHC/Iface/Ext/Ast.hs
+++ b/compiler/GHC/Iface/Ext/Ast.hs
@@ -680,7 +680,7 @@ instance ToHie (LocatedA HsWrapper) where
         (WpLet bs)      -> toHie $ EvBindContext (mkScopeA osp) (getRealSpanA osp) (L osp bs)
         (WpCompose a b) -> concatM $
           [toHie (L osp a), toHie (L osp b)]
-        (WpFun a b _ _) -> concatM $
+        (WpFun a b _)   -> concatM $
           [toHie (L osp a), toHie (L osp b)]
         (WpEvLam a) ->
           toHie $ C (EvidenceVarBind EvWrapperBind (mkScopeA osp) (getRealSpanA osp))
diff --git a/compiler/GHC/Iface/Syntax.hs b/compiler/GHC/Iface/Syntax.hs
index b2aaad5e23..39f0bd5336 100644
--- a/compiler/GHC/Iface/Syntax.hs
+++ b/compiler/GHC/Iface/Syntax.hs
@@ -230,7 +230,7 @@ data IfaceAxBranch = IfaceAxBranch { ifaxbTyVars    :: [IfaceTvBndr]
                                      -- See Note [Storing compatibility] in GHC.Core.Coercion.Axiom
 
 data IfaceConDecls
-  = IfAbstractTyCon     -- c.f TyCon.AbstractTyCon
+  = IfAbstractTyCon -- c.f TyCon.AbstractTyCon
   | IfDataTyCon [IfaceConDecl] -- Data type decls
   | IfNewTyCon  IfaceConDecl   -- Newtype decls
 
@@ -375,7 +375,7 @@ data IfaceUnfolding
 
 -- We only serialise the IdDetails of top-level Ids, and even then
 -- we only need a very limited selection.  Notably, none of the
--- implicit ones are needed here, because they are not put it
+-- implicit ones are needed here, because they are not put in
 -- interface files
 
 data IfaceIdDetails
@@ -452,9 +452,9 @@ See [https://gitlab.haskell.org/ghc/ghc/wikis/commentary/compiler/recompilation-
 -}
 
 visibleIfConDecls :: IfaceConDecls -> [IfaceConDecl]
-visibleIfConDecls IfAbstractTyCon  = []
-visibleIfConDecls (IfDataTyCon cs) = cs
-visibleIfConDecls (IfNewTyCon c)   = [c]
+visibleIfConDecls (IfAbstractTyCon {}) = []
+visibleIfConDecls (IfDataTyCon cs)     = cs
+visibleIfConDecls (IfNewTyCon c)       = [c]
 
 ifaceDeclImplicitBndrs :: IfaceDecl -> [OccName]
 --  *Excludes* the 'main' name, but *includes* the implicitly-bound names
@@ -471,9 +471,9 @@ ifaceDeclImplicitBndrs :: IfaceDecl -> [OccName]
 
 ifaceDeclImplicitBndrs (IfaceData {ifName = tc_name, ifCons = cons })
   = case cons of
-      IfAbstractTyCon -> []
-      IfNewTyCon  cd  -> mkNewTyCoOcc (occName tc_name) : ifaceConDeclImplicitBndrs cd
-      IfDataTyCon cds -> concatMap ifaceConDeclImplicitBndrs cds
+      IfAbstractTyCon {} -> []
+      IfNewTyCon  cd     -> mkNewTyCoOcc (occName tc_name) : ifaceConDeclImplicitBndrs cd
+      IfDataTyCon cds    -> concatMap ifaceConDeclImplicitBndrs cds
 
 ifaceDeclImplicitBndrs (IfaceClass { ifBody = IfAbstractClass })
   = []