Add 1+2 consts.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@89546 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/DeclBase.cpp b/lib/AST/DeclBase.cpp
index 831f552..f0eb011 100644
--- a/lib/AST/DeclBase.cpp
+++ b/lib/AST/DeclBase.cpp
@@ -119,7 +119,7 @@
 
   OS << Message;
 
-  if (NamedDecl *DN = dyn_cast_or_null<NamedDecl>(TheDecl))
+  if (const NamedDecl *DN = dyn_cast_or_null<NamedDecl>(TheDecl))
     OS << " '" << DN->getQualifiedNameAsString() << '\'';
   OS << '\n';
 }