Remove fun_infix from Funbind, as it is now in Match

One of the changes D538 introduced is to add `m_fun_id_infix` to `Match`

```lang=hs
data Match id body
  = Match {
        m_fun_id_infix :: (Maybe (Located id,Bool)),
          -- fun_id and fun_infix for functions with multiple equations
          -- only present for a RdrName. See note [fun_id in Match]
        m_pats :: [LPat id], -- The patterns
        m_type :: (Maybe (LHsType id)),
                                 -- A type signature for the result of the match
                                 -- Nothing after typechecking
        m_grhss :: (GRHSs id body)
  } deriving (Typeable)
```

This was done to track the individual locations and fixity of the
`fun_id` for each of the defining equations for a function when there
are more than one.

For example, the function `(&&&)` is defined with some prefix and some
infix equations below.

```lang=hs
    (&&&  ) [] [] =  []
    xs    &&&   [] =  xs
    (  &&&  ) [] ys =  ys
```

This means that the fun_infix is now superfluous in the `FunBind`. This
has not been removed as a potentially risky change just before 7.10 RC2,
and so must be done after.

This ticket captures that task, which includes processing these fields
through the renamer and beyond.

Ticket #9988 introduced these fields into `Match` through renaming, this
ticket it to continue through type checking and then remove it from
`FunBind` completely.

The split happened so that #9988 could land in 7.10

Trac ticket : #10061

Test Plan: ./validate

Reviewers: goldfire, austin, simonpj, bgamari

Reviewed By: bgamari

Subscribers: simonpj, thomie, mpickering

Differential Revision: https://phabricator.haskell.org/D1285

GHC Trac Issues: #10061

1 files changed, 2 insertions, 3 deletions

diff --git a/compiler/deSugar/DsBinds.hs b/compiler/deSugar/DsBinds.hs
index 93b50dfc7c..47a3419bcc 100644
--- a/compiler/deSugar/DsBinds.hs
+++ b/compiler/deSugar/DsBinds.hs
@@ -108,10 +108,9 @@ dsHsBind (VarBind { var_id = var, var_rhs = expr, var_inline = inline_regardless
         ; return (unitOL (makeCorePair dflags var' False 0 core_expr)) }
 
 dsHsBind (FunBind { fun_id = L _ fun, fun_matches = matches
-                  , fun_co_fn = co_fn, fun_tick = tick
-                  , fun_infix = inf })
+                  , fun_co_fn = co_fn, fun_tick = tick })
  = do   { dflags <- getDynFlags
-        ; (args, body) <- matchWrapper (FunRhs (idName fun) inf) matches
+        ; (args, body) <- matchWrapper (FunRhs (idName fun)) matches
         ; let body' = mkOptTickBox tick body
         ; rhs <- dsHsWrapper co_fn (mkLams args body')
         ; {- pprTrace "dsHsBind" (ppr fun <+> ppr (idInlinePragma fun)) $ -}