Update copyright dates to include 2012.


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@12843 a5019735-40e9-0310-863c-91ae7b9d1cf9
diff --git a/coregrind/m_stacks.c b/coregrind/m_stacks.c
index 0014b60..000aaa9 100644
--- a/coregrind/m_stacks.c
+++ b/coregrind/m_stacks.c
@@ -7,7 +7,7 @@
    This file is part of Valgrind, a dynamic binary instrumentation
    framework.
 
-   Copyright (C) 2000-2011 Julian Seward 
+   Copyright (C) 2000-2012 Julian Seward 
       jseward@acm.org
 
    This program is free software; you can redistribute it and/or