Update year in license files

In last year's update (D48219) it was suggested that the release manager
might want to do this, so here we go.

llvm-svn: 351194
GitOrigin-RevId: eb60fbfdb43cb8583eda1e338b3489ddef332f10
diff --git a/LICENSE.txt b/LICENSE.txt
index 14efdfa..ce09f0a 100644
--- a/LICENSE.txt
+++ b/LICENSE.txt
@@ -12,7 +12,7 @@
 University of Illinois/NCSA

 Open Source License

 

-Copyright (c) 2017-2018 by the contributors listed in CREDITS.TXT

+Copyright (c) 2017-2019 by the contributors listed in CREDITS.TXT

 

 All rights reserved.

 

@@ -49,7 +49,7 @@
 

 ==============================================================================

 

-Copyright (c) 2017-2018 by the contributors listed in CREDITS.TXT

+Copyright (c) 2017-2019 by the contributors listed in CREDITS.TXT

 

 Permission is hereby granted, free of charge, to any person obtaining a copy

 of this software and associated documentation files (the "Software"), to deal