[commit: ghc] ghc-8.2: Do Note [Improving seq] always (09249f9)

[git at git.haskell.org]

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

On branch  : ghc-8.2
Link       : http://ghc.haskell.org/trac/ghc/changeset/09249f93089517ace8aae6d0652716f6fac18e3e/ghc

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

commit 09249f93089517ace8aae6d0652716f6fac18e3e
Author: Simon Peyton Jones <simonpj at microsoft.com>
Date:   Fri Apr 7 16:19:56 2017 +0100

    Do Note [Improving seq] always
    
    This patch fixes Trac #13468, and at the same time makes the
    code simpler and more uniform.  In particular, I've eliminated
    the awkward conflict between the old built-in rule for seq
    (which elimianted a cast), and the desire to make case scrutinse
    a data type by doing type-family reduction (which adds a cast).
    
    Nice.
    
    (cherry picked from commit f0d98fc6cdde26bf43a04d9f01b6ad2f4c88f0b9)


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09249f93089517ace8aae6d0652716f6fac18e3e
 compiler/basicTypes/MkId.hs                        |  40 +-----
 compiler/simplCore/Simplify.hs                     | 138 ++++++++++++---------
 testsuite/tests/simplCore/should_compile/Makefile  |   6 +
 testsuite/tests/simplCore/should_compile/T13468.hs |  12 ++
 testsuite/tests/simplCore/should_compile/all.T     |   4 +
 5 files changed, 104 insertions(+), 96 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 09249f93089517ace8aae6d0652716f6fac18e3e