[commit: ghc] master: Testsuite: add -XUndecidableInstances to T3500a (7f37274)

[git at git.haskell.org]

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

On branch  : master
Link       : http://ghc.haskell.org/trac/ghc/changeset/7f37274d9f6de8c53cbf7fce3c39ad19cebdbbb5/ghc

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

commit 7f37274d9f6de8c53cbf7fce3c39ad19cebdbbb5
Author: Thomas Miedema <thomasmiedema at gmail.com>
Date:   Mon Jul 20 15:40:26 2015 +0200

    Testsuite: add -XUndecidableInstances to T3500a
    
    This makes the test pass again with HEAD (7.11), instead of resulting
    in:
    
      T3500a.hs:11:10: error:
          The constraint ‘C (F a)’ is no smaller than the instance head
          (Use UndecidableInstances to permit this)
          In the instance declaration for ‘C (a, b)’
    
    Test Plan: I verified that ghc-6.12.3's typechecker still loops on this
    test.
    
    Reviewers: austin, bgamari, simonpj
    
    Reviewed By: simonpj
    
    Subscribers: thomie
    
    Differential Revision: https://phabricator.haskell.org/D1079


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7f37274d9f6de8c53cbf7fce3c39ad19cebdbbb5
 testsuite/tests/typecheck/should_run/T3500a.hs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/testsuite/tests/typecheck/should_run/T3500a.hs b/testsuite/tests/typecheck/should_run/T3500a.hs
index c3adeb0..b614008 100644
--- a/testsuite/tests/typecheck/should_run/T3500a.hs
+++ b/testsuite/tests/typecheck/should_run/T3500a.hs
@@ -1,5 +1,6 @@
 {-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE TypeFamilies     #-}
+{-# LANGUAGE UndecidableInstances #-}
 
 module Main where