Fixed compilation issue.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259087 91177308-0d34-0410-b5e6-96231b3b80d8

unittests/Support/AlignOfTest.cpp

@@ -90,7 +90,7 @@ V7::~V7() {}
 V8::~V8() {}
 
 struct Abstract1 {
-  virtual ~Abstract1() = default;
+  virtual ~Abstract1() {}
   virtual void method() = 0;
 
   char c;