[commit: ghc] ghc-8.0: users-guide: Add -Wnoncanonical-semigroup-instances to relnotes (fc30ebc)

[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/fc30ebcd85ea9f7f60569b778de2d891e49cfe63/ghc

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

commit fc30ebcd85ea9f7f60569b778de2d891e49cfe63
Author: Ben Gamari <ben at smart-cactus.org>
Date:   Tue May 10 23:27:01 2016 +0200

    users-guide: Add -Wnoncanonical-semigroup-instances to relnotes


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

fc30ebcd85ea9f7f60569b778de2d891e49cfe63
 docs/users_guide/8.0.1-notes.rst | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/docs/users_guide/8.0.1-notes.rst b/docs/users_guide/8.0.1-notes.rst
index 1e394d1..4e11b77 100644
--- a/docs/users_guide/8.0.1-notes.rst
+++ b/docs/users_guide/8.0.1-notes.rst
@@ -364,6 +364,9 @@ Warnings
    ``Applicative``/``Monad``/``MonadFail`` instance definitions.
    See flag description in :ref:`options-sanity` for more details.
 
+-  Added the option :ghc-flag:`-Wnoncanonical-semigroup-instances` which
+   warns of ``Monoid`` instances where ``mappend`` is not defined in term of
+   ``Semigroup``'s ``(<>)`` operation.
 
 -  Added the :ghc-flag:`-Wmissing-pattern-synonym-signatures`
    flag. When enabled, this will issue a warning when a pattern