[commit: ghc] wip/impredicativity: Implement defaulting of <~ in simplifyTop (bd8cec5)

[git at git.haskell.org]

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

On branch  : wip/impredicativity
Link       : http://ghc.haskell.org/trac/ghc/changeset/bd8cec5d6cb5bb8c46a63a4f94103a4f0fc1f7bc/ghc

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commit bd8cec5d6cb5bb8c46a63a4f94103a4f0fc1f7bc
Author: Alejandro Serrano <trupill at gmail.com>
Date:   Fri Jul 24 10:35:41 2015 +0200

    Implement defaulting of <~ in simplifyTop
    
    When we have leftover constraints of the form sigma <~ tyvar
    or sigma <~ tyfamily on checking mode, we know try to default
    them to a type equality to solve the entire constraint set.
    
    This implementation is more a proof-of-concept. In particular,
    the part of defaulting <~ with type families is done by
    introducing a global parameter in SMonad. This implementation
    should be changed.


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bd8cec5d6cb5bb8c46a63a4f94103a4f0fc1f7bc
 compiler/typecheck/TcCanonical.hs | 11 ++++++---
 compiler/typecheck/TcSMonad.hs    | 31 ++++++++++++++++++------
 compiler/typecheck/TcSimplify.hs  | 23 ++++++++++++------
 docs/types/impredicativity.ltx    | 50 ++++++++++++++++++++++++++-------------
 4 files changed, 82 insertions(+), 33 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 bd8cec5d6cb5bb8c46a63a4f94103a4f0fc1f7bc