[commit: ghc] wip/T2893: Add missing cases for ForAllPred (8c3a134)

[git at git.haskell.org]

Repository : ssh://git@git.haskell.org/ghc

On branch  : wip/T2893
Link       : http://ghc.haskell.org/trac/ghc/changeset/8c3a134045ad4f25080996917b3fe77cb506b17b/ghc

>---------------------------------------------------------------

commit 8c3a134045ad4f25080996917b3fe77cb506b17b
Author: Simon Peyton Jones <simonpj at microsoft.com>
Date:   Wed Jan 31 12:00:43 2018 +0000

    Add missing cases for ForAllPred
    
    Should fix Trac #14744


>---------------------------------------------------------------

8c3a134045ad4f25080996917b3fe77cb506b17b
 compiler/specialise/Specialise.hs | 1 +
 compiler/typecheck/TcCanonical.hs | 0
 compiler/typecheck/TcType.hs      | 2 ++
 3 files changed, 3 insertions(+)

diff --git a/compiler/specialise/Specialise.hs b/compiler/specialise/Specialise.hs
index c4fe042..bc3e27f 100644
--- a/compiler/specialise/Specialise.hs
+++ b/compiler/specialise/Specialise.hs
@@ -2011,6 +2011,7 @@ mkCallUDs' env f args
             EqPred {}       -> True
             IrredPred {}    -> True   -- Things like (D []) where D is a
                                       -- Constraint-ranged family; Trac #7785
+            ForAllPred {}   -> True
 
 {-
 Note [Type determines value]
diff --git a/compiler/typecheck/TcType.hs b/compiler/typecheck/TcType.hs
index de37aa8..ab0519d 100644
--- a/compiler/typecheck/TcType.hs
+++ b/compiler/typecheck/TcType.hs
@@ -1983,6 +1983,7 @@ pickQuantifiablePreds qtvs theta
 
           EqPred NomEq ty1 ty2  -> quant_fun ty1 || quant_fun ty2
           IrredPred ty          -> tyCoVarsOfType ty `intersectsVarSet` qtvs
+          ForAllPred {}         -> False
 
     pick_cls_pred flex_ctxt cls tys
       = tyCoVarsOfTypes tys `intersectsVarSet` qtvs
@@ -2087,6 +2088,7 @@ isImprovementPred ty
       EqPred ReprEq _ _  -> False
       ClassPred cls _    -> classHasFds cls
       IrredPred {}       -> True -- Might have equalities after reduction?
+      ForAllPred {}      -> False
 
 {- Note [Expanding superclasses]
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~