[commit: ghc] master: Revert "Remove unnecessary isTyVar tests in TcType" (560bc28)

[git at git.haskell.org]

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

On branch  : master
Link       : http://ghc.haskell.org/trac/ghc/changeset/560bc289fc6a5b308f985d4c84e0cdf1f88c55fd/ghc

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

commit 560bc289fc6a5b308f985d4c84e0cdf1f88c55fd
Author: Ryan Scott <ryan.gl.scott at gmail.com>
Date:   Sun Jan 22 12:57:08 2017 -0500

    Revert "Remove unnecessary isTyVar tests in TcType"
    
    Summary:
    This reverts commit a0899b2f66a4102a7cf21569889381446ce63833. This is because
    removing these checks prompts panics in at least two different programs
    reported in #12785.
    
    Test Plan: ./validate
    
    Reviewers: simonpj, goldfire, bgamari, austin
    
    Subscribers: thomie
    
    Differential Revision: https://phabricator.haskell.org/D2931
    
    GHC Trac Issues: #12785


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560bc289fc6a5b308f985d4c84e0cdf1f88c55fd
 compiler/typecheck/TcType.hs                       | 24 ++++++++++++++
 .../tests/typecheck/should_compile/T12785a.hs      | 11 +++++++
 testsuite/tests/typecheck/should_compile/all.T     |  1 +
 testsuite/tests/typecheck/should_fail/T12785b.hs   | 38 ++++++++++++++++++++++
 .../tests/typecheck/should_fail/T12785b.stderr     | 26 +++++++++++++++
 testsuite/tests/typecheck/should_fail/all.T        |  1 +
 6 files changed, 101 insertions(+)

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 560bc289fc6a5b308f985d4c84e0cdf1f88c55fd