Don't mark lambda binders as OtherCon

We used to put OtherCon unfoldings on lambda binders of workers
and sometimes also join points/specializations with with the
assumption that since the wrapper would force these arguments
once we execute the RHS they would indeed be in WHNF.

This was wrong for reasons detailed in #21472. So now we purge
evaluated unfoldings from *all* lambda binders.

This fixes #21472, but at the cost of sometimes not using as efficient a
calling convention. It can also change inlining behaviour as some
occurances will no longer look like value arguments when they did
before.

As consequence we also change how we compute CBV information for
arguments slightly. We now *always* determine the CBV convention
for arguments during tidy. Earlier in the pipeline we merely mark
functions as candidates for having their arguments treated as CBV.

As before the process is described in the relevant notes:
Note [CBV Function Ids]
Note [Attaching CBV Marks to ids]
Note [Never put `OtherCon` unfoldigns on lambda binders]

-------------------------
Metric Decrease:
    T12425
    T13035
    T18223
    T18223
    T18923
    MultiLayerModulesTH_OneShot
Metric Increase:
    WWRec
-------------------------

1 files changed, 5 insertions, 5 deletions

diff --git a/compiler/GHC/Iface/Syntax.hs b/compiler/GHC/Iface/Syntax.hs
index bfd07fda8b..72f1002177 100644
--- a/compiler/GHC/Iface/Syntax.hs
+++ b/compiler/GHC/Iface/Syntax.hs
@@ -381,7 +381,7 @@ data IfaceUnfolding
 
 data IfaceIdDetails
   = IfVanillaId
-  | IfStrictWorkerId [CbvMark]
+  | IfWorkerLikeId [CbvMark]
   | IfRecSelId (Either IfaceTyCon IfaceDecl) Bool
   | IfDFunId
 
@@ -1462,7 +1462,7 @@ instance Outputable IfaceConAlt where
 ------------------
 instance Outputable IfaceIdDetails where
   ppr IfVanillaId       = Outputable.empty
-  ppr (IfStrictWorkerId dmd) = text "StrWork" <> parens (ppr dmd)
+  ppr (IfWorkerLikeId dmd) = text "StrWork" <> parens (ppr dmd)
   ppr (IfRecSelId tc b) = text "RecSel" <+> ppr tc
                           <+> if b
                                 then text "<naughty>"
@@ -2227,14 +2227,14 @@ instance Binary IfaceAnnotation where
 instance Binary IfaceIdDetails where
     put_ bh IfVanillaId      = putByte bh 0
     put_ bh (IfRecSelId a b) = putByte bh 1 >> put_ bh a >> put_ bh b
-    put_ bh (IfStrictWorkerId dmds) = putByte bh 2 >> put_ bh dmds
+    put_ bh (IfWorkerLikeId dmds) = putByte bh 2 >> put_ bh dmds
     put_ bh IfDFunId         = putByte bh 3
     get bh = do
         h <- getByte bh
         case h of
             0 -> return IfVanillaId
             1 -> do { a <- get bh; b <- get bh; return (IfRecSelId a b) }
-            2 -> do { dmds <- get bh; return (IfStrictWorkerId dmds) }
+            2 -> do { dmds <- get bh; return (IfWorkerLikeId dmds) }
             _ -> return IfDFunId
 
 instance Binary IfaceInfoItem where
@@ -2592,7 +2592,7 @@ instance NFData IfaceBang where
 instance NFData IfaceIdDetails where
   rnf = \case
     IfVanillaId -> ()
-    IfStrictWorkerId dmds -> dmds `seqList` ()
+    IfWorkerLikeId dmds -> dmds `seqList` ()
     IfRecSelId (Left tycon) b -> rnf tycon `seq` rnf b
     IfRecSelId (Right decl) b -> rnf decl `seq` rnf b
     IfDFunId -> ()