Declarations processed in unexpected order in the presence of TH declaration splices

In ghc-7.8 reify returns only first data type that have an instance, here is a code:

Test.hs

{-# LANGUAGE TemplateHaskell #-}
module Test where

import Language.Haskell.TH

class C a

inner :: ExpQ
inner = do
  ClassI _ instances <- reify ''C
  let sh = show instances
  [| sh |]

def :: String -> DecsQ
def x =
  let dn = mkName x
  in do dt <- dataD (cxt []) dn [] [] [] 
        i <- instanceD (cxt []) (appT (conT ''C) (conT dn)) [] -- [d| instance C $(cn) |]
        return [dt,i]

test :: ExpQ
test = [| print $inner |]

test.hs

{-# LANGUAGE TemplateHaskell #-}

import Test

def "A"
def "B"

main = $(test)

running test returns:

"[InstanceD [] (AppT (ConT Test.C) (ConT Main.A)) []]"

under 7.6 test returns:

"[InstanceD [] (AppT (ConT Test.C) (ContT Main.B) [], InstanceD [] (AppT (ConT Test.C) (ConT Main.A) []]"

Trac metadata

Trac field	Value
Version	7.8.3
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
Test case
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