[commit: ghc] master: Refactor pruning of implication constraints (818e027)

[git at git.haskell.org]

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

On branch  : master
Link       : http://ghc.haskell.org/trac/ghc/changeset/818e027e2db2ac291c44a5e07ae151505f3908b8/ghc

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commit 818e027e2db2ac291c44a5e07ae151505f3908b8
Author: Simon Peyton Jones <simonpj at microsoft.com>
Date:   Fri Dec 9 17:32:07 2016 +0000

    Refactor pruning of implication constraints
    
    We try to prune solved implication constraints, but it's a
    bit tricky because of our desire to correctly report unused
    'givens'.  This patch improves matters a bit... in tracig some
    other bug I saw lots of empty constraints lying around!


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818e027e2db2ac291c44a5e07ae151505f3908b8
 compiler/typecheck/TcInstDcls.hs |  2 ++
 compiler/typecheck/TcRnTypes.hs  | 15 +++++++--
 compiler/typecheck/TcSMonad.hs   |  1 +
 compiler/typecheck/TcSimplify.hs | 71 +++++++++++++++++++++++++---------------
 compiler/typecheck/TcUnify.hs    |  1 +
 5 files changed, 60 insertions(+), 30 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 818e027e2db2ac291c44a5e07ae151505f3908b8