Roll-back r250822.

Summary: It breaks the build for the ASTMatchers

Subscribers: klimek, cfe-commits

Differential Revision: http://reviews.llvm.org/D13893

llvm-svn: 250827
diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
index 5e3d762..59347de 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -164,7 +164,7 @@
 // PCH validator implementation
 //===----------------------------------------------------------------------===//
 
-ASTReaderListener::~ASTReaderListener() = default;
+ASTReaderListener::~ASTReaderListener() {}
 
 /// \brief Compare the given set of language options against an existing set of
 /// language options.