Tighten types a bit. No functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@171894 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Parse/ParseDeclCXX.cpp b/lib/Parse/ParseDeclCXX.cpp
index 2638983..64e529b 100644
--- a/lib/Parse/ParseDeclCXX.cpp
+++ b/lib/Parse/ParseDeclCXX.cpp
@@ -2162,7 +2162,7 @@
     // this call will *not* return the created decl; It will return null.
     // See Sema::ActOnCXXMemberDeclarator for details.
 
-    Decl *ThisDecl = 0;
+    NamedDecl *ThisDecl = 0;
     if (DS.isFriendSpecified()) {
       // C++11 [dcl.attr.grammar] p4: If an attribute-specifier-seq appertains 
       // to a friend declaration, that declaration shall be a definition.