Fix warning introduced in r238190 about lack of virtual destructor in MCObjectFileInfo.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238197 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/MC/MCObjectFileInfo.h

@@ -188,6 +188,8 @@ protected:
   MCSection *XDataSection;
 
 public:
+  virtual ~MCObjectFileInfo() { };
+
   void InitMCObjectFileInfo(StringRef TT, Reloc::Model RM, CodeModel::Model CM,
                             MCContext &ctx);