Fix uninitialized variable warnings. NFCI.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@374876 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/ASTImporter.cpp b/lib/AST/ASTImporter.cpp
index 20539fe..a549cf9 100644
--- a/lib/AST/ASTImporter.cpp
+++ b/lib/AST/ASTImporter.cpp
@@ -2579,10 +2579,10 @@
   }
 
   // Import the major distinguishing characteristics of this record.
-  DeclContext *DC, *LexicalDC;
+  DeclContext *DC = nullptr, *LexicalDC = nullptr;
   DeclarationName Name;
   SourceLocation Loc;
-  NamedDecl *ToD;
+  NamedDecl *ToD = nullptr;
   if (Error Err = ImportDeclParts(D, DC, LexicalDC, Name, ToD, Loc))
     return std::move(Err);
   if (ToD)