GHC reports missing INLINABLE pragmas in vector and ghc-prim

When compiling a program with GHC 8.4.3, vector 0.12.0.1 (with a dependency on primitive 0.6.4.0) and -Weverything, I get several warnings that INLINABLE pragmas should be added to the vector and ghc-prim packages.

It would be nicer if these warnings didn't happen, even with -Weverything. Also, perhaps there are optimization opportunities that are lost.

A somewhat reduced example (can be reduced further by removing the function definitions and unused imports that creates):

{-# OPTIONS_GHC -Wall-missed-specialisations #-}
{-# LANGUAGE MultiParamTypeClasses, TypeFamilies #-}

module Warnings2 where

import GHC.Base (liftM)
import qualified Data.Vector.Generic.Base as G (Vector, basicUnsafeFreeze,
  basicUnsafeThaw, basicLength, basicUnsafeSlice, basicUnsafeIndexM,
  basicUnsafeCopy, elemseq)
import qualified Data.Vector.Generic.Mutable.Base as GM (MVector, basicLength,
  basicUnsafeSlice, basicOverlaps, basicUnsafeNew, basicInitialize,
  basicUnsafeReplicate, basicUnsafeRead, basicUnsafeWrite, basicClear, basicSet,
  basicUnsafeCopy, basicUnsafeMove, basicUnsafeGrow)
import qualified Data.Vector.Unboxed as U (Unbox, Vector)
import qualified Data.Vector.Unboxed.Mutable as U (MVector)

newtype T = T () deriving (Show, Eq, Ord)
newtype C = C (T, U.Vector T) deriving (Show, Eq, Ord)

instance U.Unbox T

newtype instance U.MVector s T = MV_T (U.MVector s ())
instance GM.MVector U.MVector T where
  basicLength (MV_T mv) = GM.basicLength mv
  basicUnsafeSlice i l (MV_T mv) = MV_T (GM.basicUnsafeSlice i l mv)
  basicOverlaps (MV_T mv1) (MV_T mv2) = GM.basicOverlaps mv1 mv2
  basicUnsafeNew l = MV_T `liftM` GM.basicUnsafeNew l
  basicInitialize (MV_T mv) = GM.basicInitialize mv
  basicUnsafeReplicate l _ = MV_T `liftM` GM.basicUnsafeReplicate l ()
  basicUnsafeRead (MV_T mv) i = const (T ()) `liftM` GM.basicUnsafeRead mv i
  basicUnsafeWrite (MV_T mv) i _ = GM.basicUnsafeWrite mv i ()
  basicClear (MV_T mv) = GM.basicClear mv
  basicSet (MV_T mv) x = GM.basicSet mv ()
  basicUnsafeCopy (MV_T mv1) (MV_T mv2) = GM.basicUnsafeCopy mv1 mv2
  basicUnsafeMove (MV_T mv1) (MV_T mv2) = GM.basicUnsafeMove mv1 mv2
  basicUnsafeGrow (MV_T mv) l = MV_T `liftM` GM.basicUnsafeGrow mv l

newtype instance U.Vector T = V_T (U.Vector ())
instance G.Vector U.Vector T where
  basicUnsafeFreeze (MV_T mv) = V_T `liftM` G.basicUnsafeFreeze mv
  basicUnsafeThaw (V_T v) = MV_T `liftM` G.basicUnsafeThaw v
  basicLength (V_T v) = G.basicLength v
  basicUnsafeSlice i l (V_T v) = V_T (G.basicUnsafeSlice i l v)
  basicUnsafeIndexM (V_T v) i = const (T ()) `liftM` G.basicUnsafeIndexM v i
  basicUnsafeCopy (MV_T mv) (V_T v) = G.basicUnsafeCopy mv v
  elemseq (V_T v) _ = G.elemseq v ()

The warnings:

`lineno=1 marks=16,31,46 src/Warnings2.hs: warning: Could not specialise imported function ‘Data.Vector.Unboxed.wcshowsPrec’ when specialising ‘Data.Vector.Unboxed.fShowVector_cshowsPrec’ when specialising ‘Data.Vector.Unboxed.$fShowVector’ Probable fix: add INLINABLE pragma on ‘Data.Vector.Unboxed.wcshowsPrec’

src/Warnings2.hs: warning: Could not specialise imported function ‘Data.Vector.Unboxed.fShowVector_cshow’ when specialising ‘Data.Vector.Unboxed.$fShowVector’ Probable fix: add INLINABLE pragma on ‘Data.Vector.Unboxed.fShowVector_cshow’

src/Warnings2.hs: warning: Could not specialise imported function ‘Data.Vector.Unboxed.fShowVector_cshowList’ when specialising ‘Data.Vector.Unboxed.$fShowVector’ Probable fix: add INLINABLE pragma on ‘Data.Vector.Unboxed.fShowVector_cshowList’

src/Warnings2.hs: warning: Could not specialise imported function ‘ghc-prim-0.5.2.0:GHC.Classes.wc==’ when specialising ‘ghc-prim-0.5.2.0:GHC.Classes.fEq(,)_c==’ Probable fix: add INLINABLE pragma on ‘ghc-prim-0.5.2.0:GHC.Classes.wc==’

src/Warnings2.hs: warning: Could not specialise imported function ‘Data.Vector.Unboxed.fOrdVector_cmax’ when specialising ‘Data.Vector.Unboxed.$fOrdVector’ Probable fix: add INLINABLE pragma on ‘Data.Vector.Unboxed.fOrdVector_cmax’

src/Warnings2.hs: warning: Could not specialise imported function ‘Data.Vector.Unboxed.fOrdVector_cmin’ when specialising ‘Data.Vector.Unboxed.$fOrdVector’ Probable fix: add INLINABLE pragma on ‘Data.Vector.Unboxed.fOrdVector_cmin’

src/Warnings2.hs: warning: Could not specialise imported function ‘ghc-prim-0.5.2.0:GHC.Classes.wc>=’ when specialising ‘ghc-prim-0.5.2.0:GHC.Classes.fOrd(,)_c>=’ Probable fix: add INLINABLE pragma on ‘ghc-prim-0.5.2.0:GHC.Classes.wc>=’

src/Warnings2.hs: warning: Could not specialise imported function ‘ghc-prim-0.5.2.0:GHC.Classes.wc<’ when specialising ‘ghc-prim-0.5.2.0:GHC.Classes.fOrd(,)_c<’ Probable fix: add INLINABLE pragma on ‘ghc-prim-0.5.2.0:GHC.Classes.wc<’

src/Warnings2.hs: warning: Could not specialise imported function ‘ghc-prim-0.5.2.0:GHC.Classes.wc<=’ when specialising ‘ghc-prim-0.5.2.0:GHC.Classes.fOrd(,)_c<=’ Probable fix: add INLINABLE pragma on ‘ghc-prim-0.5.2.0:GHC.Classes.wc<=’

src/Warnings2.hs: warning: Could not specialise imported function ‘ghc-prim-0.5.2.0:GHC.Classes.wccompare’ when specialising ‘ghc-prim-0.5.2.0:GHC.Classes.fOrd(,)_ccompare’ Probable fix: add INLINABLE pragma on ‘ghc-prim-0.5.2.0:GHC.Classes.wccompare’ `