[yaml2obj][ELF] Add a virtual destructor to the ELFYAML::Section class

to prevent memory leaks.

llvm-svn: 206969

include/llvm/Object/ELFYAML.h

@@ -79,6 +79,7 @@ struct Section {
   StringRef Info;
   llvm::yaml::Hex64 AddressAlign;
   Section(SectionKind Kind) : Kind(Kind) {}
+  virtual ~Section();
 };
 struct RawContentSection : Section {
   object::yaml::BinaryRef Content;

lib/Object/ELFYAML.cpp

@@ -14,6 +14,9 @@
 #include "llvm/Object/ELFYAML.h"
 
 namespace llvm {
+
+ELFYAML::Section ::~Section() {}
+
 namespace yaml {
 
 void