[commit: ghc] master: Be more careful when iterating the constraint-simpifier loop (fixes Trac #8474) (54717c8)

[git at git.haskell.org]

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

On branch  : master
Link       : http://ghc.haskell.org/trac/ghc/changeset/54717c8218cb27b1f1f56ba019c17494556f766c/ghc

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commit 54717c8218cb27b1f1f56ba019c17494556f766c
Author: Simon Peyton Jones <simonpj at microsoft.com>
Date:   Fri Oct 25 14:35:37 2013 +0100

    Be more careful when iterating the constraint-simpifier loop (fixes Trac #8474)
    
    We were (uselessly) iterating the simplification loop an exponential
    number of times.  Lovely simple test case showed this up.
    
    See Note [Cutting off simpl_loop] in TcSimplify


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54717c8218cb27b1f1f56ba019c17494556f766c
 compiler/typecheck/TcSMonad.lhs   |   51 +++++++++++++++++++++++++++----------
 compiler/typecheck/TcSimplify.lhs |   48 +++++++++++++++++++++++++++++++---
 2 files changed, 83 insertions(+), 16 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 54717c8218cb27b1f1f56ba019c17494556f766c