Remove `setUnfoldingInfoLazily`

The definition of `setUnfoldingInfoLazily` is exactly the same as
`setUnfoldingInfo` and is only used in one place, `TcIface`.

They were made equivalent in 2010 in
2ff2497dc374175b8ed81446258baf208d1f3e6e with the commit message.

{{{
commit 2ff2497dc374175b8ed81446258baf208d1f3e6e
Author: Ian Lynagh <igloo@earth.li>  Wed Oct 20 15:37:10 2010
Committer:      Ian Lynagh <igloo@earth.li>  Wed Oct 20 15:37:10 2010
Original File:  compiler/basicTypes/IdInfo.lhs

Don't seq unfoldings
We generate intermediate unfoldings which are just thrown away, so
evaluating them is a waste of time.
}}}

Closes #12453

4 files changed, 4 insertions, 14 deletions

diff --git a/compiler/basicTypes/Id.hs b/compiler/basicTypes/Id.hs
index 387de1ec83..4e8847beee 100644
--- a/compiler/basicTypes/Id.hs
+++ b/compiler/basicTypes/Id.hs
@@ -90,7 +90,6 @@ module Id (
         idOccInfo,
 
         -- ** Writing 'IdInfo' fields
-        setIdUnfoldingLazily,
         setIdUnfolding,
         setIdArity,
         setIdCallArity,
@@ -139,8 +138,7 @@ import Util
 import StaticFlags
 
 -- infixl so you can say (id `set` a `set` b)
-infixl  1 `setIdUnfoldingLazily`,
-          `setIdUnfolding`,
+infixl  1 `setIdUnfolding`,
           `setIdArity`,
           `setIdCallArity`,
           `setIdOccInfo`,
@@ -606,9 +604,6 @@ realIdUnfolding :: Id -> Unfolding
 -- Expose the unfolding if there is one, including for loop breakers
 realIdUnfolding id = unfoldingInfo (idInfo id)
 
-setIdUnfoldingLazily :: Id -> Unfolding -> Id
-setIdUnfoldingLazily id unfolding = modifyIdInfo (`setUnfoldingInfoLazily` unfolding) id
-
 setIdUnfolding :: Id -> Unfolding -> Id
 setIdUnfolding id unfolding = modifyIdInfo (`setUnfoldingInfo` unfolding) id
 
diff --git a/compiler/basicTypes/IdInfo.hs b/compiler/basicTypes/IdInfo.hs
index 0cd2e95c52..4d10f20069 100644
--- a/compiler/basicTypes/IdInfo.hs
+++ b/compiler/basicTypes/IdInfo.hs
@@ -38,7 +38,7 @@ module IdInfo (
         demandInfo, setDemandInfo, pprStrictness,
 
         -- ** Unfolding Info
-        unfoldingInfo, setUnfoldingInfo, setUnfoldingInfoLazily,
+        unfoldingInfo, setUnfoldingInfo,
 
         -- ** The InlinePragInfo type
         InlinePragInfo,
@@ -230,11 +230,6 @@ setOccInfo :: IdInfo -> OccInfo -> IdInfo
 setOccInfo        info oc = oc `seq` info { occInfo = oc }
         -- Try to avoid spack leaks by seq'ing
 
-setUnfoldingInfoLazily :: IdInfo -> Unfolding -> IdInfo
-setUnfoldingInfoLazily info uf  -- Lazy variant to avoid looking at the
-  =                             -- unfolding of an imported Id unless necessary
-    info { unfoldingInfo = uf } -- (In this case the demand-zapping is redundant.)
-
 setUnfoldingInfo :: IdInfo -> Unfolding -> IdInfo
 setUnfoldingInfo info uf
   = -- We don't seq the unfolding, as we generate intermediate
diff --git a/compiler/iface/TcIface.hs b/compiler/iface/TcIface.hs
index f8e9505f1c..56c5a5aaf0 100644
--- a/compiler/iface/TcIface.hs
+++ b/compiler/iface/TcIface.hs
@@ -1232,7 +1232,7 @@ tcIdInfo ignore_prags name ty info
       = do { unf <- tcUnfolding name ty info if_unf
            ; let info1 | lb        = info `setOccInfo` strongLoopBreaker
                        | otherwise = info
-           ; return (info1 `setUnfoldingInfoLazily` unf) }
+           ; return (info1 `setUnfoldingInfo` unf) }
 
 tcUnfolding :: Name -> Type -> IdInfo -> IfaceUnfolding -> IfL Unfolding
 tcUnfolding name _ info (IfCoreUnfold stable if_expr)
diff --git a/compiler/vectorise/Vectorise.hs b/compiler/vectorise/Vectorise.hs
index 77561ffcd8..b78db7c6da 100644
--- a/compiler/vectorise/Vectorise.hs
+++ b/compiler/vectorise/Vectorise.hs
@@ -315,7 +315,7 @@ vectTopBinder var inline expr
                   (text "Inferred type" <+> ppr vdty)
               }
           -- Make the vectorised version of binding's name, and set the unfolding used for inlining
-      ; var' <- liftM (`setIdUnfoldingLazily` unfolding)
+      ; var' <- liftM (`setIdUnfolding` unfolding)
                 $  mkVectId var vty
 
           -- Add the mapping between the plain and vectorised name to the state.