-fsolve-constant-dicts is not very robust when dealing with GADTs

I expected -fsolve-constant-dicts to nail #9701, it didn't fire at all but a slightly modified version does.

{-# LANGUAGE GADTs #-}    
{-# LANGUAGE TypeApplications #-}    
module Foo where    
      
data Silly a where    
  Silly :: Ord a => a -> Silly a    
      
isItSilly :: a -> Silly a -> Bool    
isItSilly a (Silly x) = a < x    

isItSillyIntTA :: Int -> Silly Int -> Bool
isItSillyIntTA = isItSilly @Int
      
isItSillyInt :: Int -> Silly Int  -> Bool    
isItSillyInt  a x = isItSilly a x    
      
isItSillyInt2 :: Int -> Silly Int -> Bool    
isItSillyInt2 a (Silly x) = a < x          
                                                                                
isItSillyInt3 :: Int -> Silly Int -> Bool                                     
isItSillyInt3 a (Silly x) = isItSilly a (Silly x)

Both versions 2 and 3 specialise nicely using the Int Ord dictionary. The first two versions don't. I'm unsure whether it *should* fire or not but I am making this ticket to record this fact.

Clonable code and core dump - https://gist.github.com/mpickering/f84a5f842861211e8e731c63e82d5c01

Trac metadata

Trac field	Value
Version	8.2.1
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
Test case
Differential revisions
BlockedBy
Related
Blocking
CC	dfeuer
Operating system
Architecture