[commit: ghc] wip/T2893: Fix a bunch of buglets in QuantifiedConstraints (60f6824)

[git at git.haskell.org]

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

On branch  : wip/T2893
Link       : http://ghc.haskell.org/trac/ghc/changeset/60f682407eefdb7884d12ba43d00add0c1ca9245/ghc

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

commit 60f682407eefdb7884d12ba43d00add0c1ca9245
Author: Simon Peyton Jones <simonpj at microsoft.com>
Date:   Tue Feb 27 13:43:26 2018 +0000

    Fix a bunch of buglets in QuantifiedConstraints
    
    * Freshen tyvars in Inst.instDFunType
    
    * Freshen tyvars in TcCanonical.solveForAll
    
    * Define TcSMonad.mightMatchLater, and use it (fixes Trac #14833)
    
    * Add testsuite directry tests/quantified-constraints/, and start
      to populate it


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

60f682407eefdb7884d12ba43d00add0c1ca9245
 compiler/typecheck/Inst.hs                         |  8 ++++--
 compiler/typecheck/TcCanonical.hs                  | 18 ++++++++-----
 compiler/typecheck/TcEvidence.hs                   |  2 --
 compiler/typecheck/TcInteract.hs                   | 30 ++++++++++------------
 compiler/typecheck/TcSMonad.hs                     | 19 +++++++-------
 compiler/typecheck/TcValidity.hs                   |  3 ++-
 compiler/types/Type.hs                             |  0
 testsuite/tests/quantified-constraints/T14833.hs   | 28 ++++++++++++++++++++
 .../T2893.hs                                       |  0
 .../T2893a.hs                                      |  0
 testsuite/tests/quantified-constraints/T2893b.hs   | 24 +++++++++++++++++
 testsuite/tests/quantified-constraints/all.T       |  4 +++
 testsuite/tests/typecheck/should_compile/all.T     |  2 --
 13 files changed, 100 insertions(+), 38 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 60f682407eefdb7884d12ba43d00add0c1ca9245