[commit: ghc] master: Tighten up constraint solve order for RULES (6b0cf0e)

[git at git.haskell.org]

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

On branch  : master
Link       : http://ghc.haskell.org/trac/ghc/changeset/6b0cf0e07605d2cde9b4e13b40f52628b6fe64ec/ghc

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commit 6b0cf0e07605d2cde9b4e13b40f52628b6fe64ec
Author: Simon Peyton Jones <simonpj at microsoft.com>
Date:   Wed Jan 14 10:53:49 2015 +0000

    Tighten up constraint solve order for RULES
    
    The main point is described in Note [Solve order for RULES].
    I'm not sure if the potential bug described there could actually
    happen, but I bet it could.  Anyway, this patch explicitly solves
    LHS constraints and *then* RHS constraints (see the Note).
    
    I also moved simplifyRule from TcSimplify (a large module) to
    TcRules (a small one), which brings related code together.
    It did mean I had to export runTcS from TcSimplify, but I think
    that's a price worth paying.


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6b0cf0e07605d2cde9b4e13b40f52628b6fe64ec
 compiler/typecheck/TcRules.hs                      | 243 ++++++++++++++-------
 compiler/typecheck/TcSimplify.hs                   |  67 +-----
 testsuite/tests/typecheck/should_fail/T5853.stderr |  19 +-
 3 files changed, 181 insertions(+), 148 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 6b0cf0e07605d2cde9b4e13b40f52628b6fe64ec