Add virtual destructor. Whoops!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@145044 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Analysis/CaptureTracking.h

@@ -37,6 +37,8 @@ namespace llvm {
   /// addition to the interface here, you'll need to provide your own getters
   /// to see whether anything was captured.
   struct CaptureTracker {
+    virtual ~CaptureTracker();
+
     /// tooManyUses - The depth of traversal has breached a limit. There may be
     /// capturing instructions that will not be passed into captured().
     virtual void tooManyUses() = 0;

lib/Analysis/CaptureTracking.cpp

@@ -19,6 +19,8 @@
 #include "llvm/Analysis/CaptureTracking.h"
 using namespace llvm;
 
+CaptureTracker::~CaptureTracker() {}
+
 namespace {
   struct SimpleCaptureTracker : public CaptureTracker {
     explicit SimpleCaptureTracker(bool ReturnCaptures)