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
-------------------------

2 files changed, 4 insertions, 10 deletions

diff --git a/testsuite/tests/arityanal/should_compile/Arity11.stderr b/testsuite/tests/arityanal/should_compile/Arity11.stderr
index a4f2e38b53..7c7451a6d7 100644
--- a/testsuite/tests/arityanal/should_compile/Arity11.stderr
+++ b/testsuite/tests/arityanal/should_compile/Arity11.stderr
@@ -142,7 +142,4 @@ f11 :: (Integer, Integer)
 f11 = (F11.f4, F11.f1)
 
 
------- Local rules for imported ids --------
-"SPEC fib @Integer @Integer" forall ($dEq :: Eq Integer) ($dNum :: Num Integer) ($dNum1 :: Num Integer). fib @Integer @Integer $dEq $dNum $dNum1 = F11.f11_fib
-
 
diff --git a/testsuite/tests/arityanal/should_compile/T18793.stderr b/testsuite/tests/arityanal/should_compile/T18793.stderr
index 13ca1c65f5..728108a331 100644
--- a/testsuite/tests/arityanal/should_compile/T18793.stderr
+++ b/testsuite/tests/arityanal/should_compile/T18793.stderr
@@ -10,12 +10,9 @@ stuff = \ (i :: Int) -> case i of i1 { GHC.Types.I# ipv -> GHC.Types.: @Int i1 (
 Rec {
 -- RHS size: {terms: 23, types: 11, coercions: 0, joins: 0/0}
 T18793.$wgo1 [InlPrag=[2], Occ=LoopBreaker] :: [Int] -> GHC.Prim.Int# -> GHC.Prim.Int#
-[GblId[StrictWorker([!, ~])], Arity=2, Str=<1L><L>, Unf=OtherCon []]
+[GblId[StrictWorker([!])], Arity=2, Str=<1L><L>, Unf=OtherCon []]
 T18793.$wgo1
-  = \ (ds
-         :: [Int]
-         Unf=OtherCon [])
-      (ww :: GHC.Prim.Int#) ->
+  = \ (ds :: [Int]) (ww :: GHC.Prim.Int#) ->
       case ds of {
         [] -> ww;
         : y ys ->
@@ -35,8 +32,8 @@ T18793.f_go1 [InlPrag=[2]] :: [Int] -> Int -> Int
  Str=<1L><1!P(L)>,
  Cpr=1,
  Unf=Unf{Src=InlineStable, TopLvl=True, Value=True, ConLike=True, WorkFree=True, Expandable=True, Guidance=ALWAYS_IF(arity=2,unsat_ok=True,boring_ok=False)
-         Tmpl= \ (ds [Occ=Once1] :: [Int]) (eta [Occ=Once1!] :: Int) -> case eta of { GHC.Types.I# ww [Occ=Once1] -> case T18793.$wgo1 ds ww of ww1 [Occ=Once1] { __DEFAULT -> GHC.Types.I# ww1 } }}]
-T18793.f_go1 = \ (ds :: [Int]) (eta :: Int) -> case eta of { GHC.Types.I# ww -> case T18793.$wgo1 ds ww of ww1 { __DEFAULT -> GHC.Types.I# ww1 } }
+         Tmpl= \ (ds [Occ=Once1] :: [Int]) (eta [Occ=Once1!, OS=OneShot] :: Int) -> case eta of { GHC.Types.I# ww [Occ=Once1] -> case T18793.$wgo1 ds ww of ww1 [Occ=Once1] { __DEFAULT -> GHC.Types.I# ww1 } }}]
+T18793.f_go1 = \ (ds :: [Int]) (eta [OS=OneShot] :: Int) -> case eta of { GHC.Types.I# ww -> case T18793.$wgo1 ds ww of ww1 { __DEFAULT -> GHC.Types.I# ww1 } }
 
 -- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
 T18793.f2 :: Int