Give a default implementation for ASTDeserializationListener's methods, no functionality change.

llvm-svn: 116506
diff --git a/clang/lib/Serialization/ASTCommon.cpp b/clang/lib/Serialization/ASTCommon.cpp
index 77c1aff..d5b7371 100644
--- a/clang/lib/Serialization/ASTCommon.cpp
+++ b/clang/lib/Serialization/ASTCommon.cpp
@@ -12,11 +12,15 @@
 //===----------------------------------------------------------------------===//
 
 #include "ASTCommon.h"
+#include "clang/Serialization/ASTDeserializationListener.h"
 #include "clang/Basic/IdentifierTable.h"
 #include "llvm/ADT/StringExtras.h"
 
 using namespace clang;
 
+// Give ASTDeserializationListener's VTable a home.
+ASTDeserializationListener::~ASTDeserializationListener() { }
+
 serialization::TypeIdx
 serialization::TypeIdxFromBuiltin(const BuiltinType *BT) {
   unsigned ID = 0;