Revert r299672: Add a virtual destructor to a class with virtual methods.

Reason: breaks sanitizers builds.

Original Differential Revision: https://reviews.llvm.org/D317

llvm-svn: 299679

compiler-rt/lib/sanitizer_common/sanitizer_flag_parser.h

@@ -22,7 +22,6 @@ namespace __sanitizer {
 
 class FlagHandlerBase {
  public:
-  virtual ~FlagHandlerBase() {}
   virtual bool Parse(const char *value) { return false; }
 };