[commit: ghc] master: Remove duplicate quantified constraints (a169149)

[git at git.haskell.org]

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

On branch  : master
Link       : http://ghc.haskell.org/trac/ghc/changeset/a169149ce80de3676adb3ece43d5164b6a875b9c/ghc

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

commit a169149ce80de3676adb3ece43d5164b6a875b9c
Author: Simon Peyton Jones <simonpj at microsoft.com>
Date:   Mon Jun 11 13:55:56 2018 +0100

    Remove duplicate quantified constraints
    
    This is an easy fix for Trac #15244: just avoid adding
    the same quantified Given constraint to the inert set twice.
    
    See TcSMonad Note [Do not add duplicate quantified instances].


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

a169149ce80de3676adb3ece43d5164b6a875b9c
 compiler/typecheck/TcInteract.hs                 | 36 +++++++++++--
 compiler/typecheck/TcSMonad.hs                   | 56 +++++++++----------
 testsuite/tests/quantified-constraints/T15244.hs | 69 ++++++++++++++++++++++++
 testsuite/tests/quantified-constraints/all.T     |  1 +
 4 files changed, 131 insertions(+), 31 deletions(-)

Diff suppressed because of size. To see it, use:

    git diff-tree --root --patch-with-stat --no-color --find-copies-harder --ignore-space-at-eol --cc a169149ce80de3676adb3ece43d5164b6a875b9c