[commit: ghc] master: Bump stm submodule (2671ec5)

[git at git.haskell.org]

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

On branch  : master
Link       : http://ghc.haskell.org/trac/ghc/changeset/2671ec595b8a68d0dcb432834daa330cf21a68b9/ghc

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

commit 2671ec595b8a68d0dcb432834daa330cf21a68b9
Author: Ben Gamari <ben at smart-cactus.org>
Date:   Mon Aug 20 15:07:12 2018 -0400

    Bump stm submodule


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

2671ec595b8a68d0dcb432834daa330cf21a68b9
 libraries/stm | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libraries/stm b/libraries/stm
index 4c24db6..4a1deb9 160000
--- a/libraries/stm
+++ b/libraries/stm
@@ -1 +1 @@
-Subproject commit 4c24db6071fc1319232934562f7dbed45d498831
+Subproject commit 4a1deb98fc95e55d8a6762a7dfec1a7dfa8b49b2