[llvm] Adding vdtor to fix warning.

llvm-svn: 238494
diff --git a/llvm/tools/llvm-objdump/llvm-objdump.cpp b/llvm/tools/llvm-objdump/llvm-objdump.cpp
index a78d1d2..ae3fb9d 100644
--- a/llvm/tools/llvm-objdump/llvm-objdump.cpp
+++ b/llvm/tools/llvm-objdump/llvm-objdump.cpp
@@ -204,6 +204,7 @@
 namespace {
 class PrettyPrinter {
 public:
+  virtual ~PrettyPrinter(){}
   virtual void printInst(MCInstPrinter &IP, const MCInst *MI, bool ShowRawInsn,
                          ArrayRef<uint8_t> Bytes, uint64_t Address,
                          raw_ostream &OS, StringRef Annot,