[commit: ghc] ghc-8.0: Improve error handling in TcRnMonad (5662cea)

[git at git.haskell.org]

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

On branch  : ghc-8.0
Link       : http://ghc.haskell.org/trac/ghc/changeset/5662ceaeb4da4fdee0f9fc01f72855168471377f/ghc

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

commit 5662ceaeb4da4fdee0f9fc01f72855168471377f
Author: Simon Peyton Jones <simonpj at microsoft.com>
Date:   Wed Oct 5 22:00:02 2016 +0100

    Improve error handling in TcRnMonad
    
    See Note [Constraints and errors] in TcRnMonad.  This
    patch fixes Trac #12124 in quite a neat way.
    
    (cherry picked from commit 465c6c5d15f8fb54afb78408f3a79e75e74d2cd4)


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

5662ceaeb4da4fdee0f9fc01f72855168471377f
 compiler/typecheck/TcRnMonad.hs                    | 60 +++++++++++++---------
 compiler/typecheck/TcSplice.hs                     |  2 +-
 .../should_fail/CustomTypeErrors02.stderr          |  5 --
 testsuite/tests/typecheck/should_fail/T12124.hs    |  8 +++
 .../should_fail/T12124.srderr}                     |  0
 .../tests/typecheck/should_fail/T12124.stderr      |  9 ++++
 testsuite/tests/typecheck/should_fail/T8142.stderr | 10 ----
 testsuite/tests/typecheck/should_fail/all.T        |  1 +
 8 files changed, 56 insertions(+), 39 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 5662ceaeb4da4fdee0f9fc01f72855168471377f