llvm-cfi-verify fixed GraphBuilder memory leak.

[hctim]

Summary

Fixed memleak when deleting orphaned nodes (clean up the whole chain instead of just the first node).

Thanks ASAN team >;)

[vlad.tsyrklevich]

Could this be part of the change this code is introduced in instead?

[hctim]

Backpatched into D38427.

tools/llvm-cfi-verify/GraphBuilder.cpp

for (ControlFlowNode *FlowNode = BranchNode->Target; FlowNode;
          FlowNode = FlowNode->Next)
       CFNs.insert(FlowNode);
 
     for (ControlFlowNode *FlowNode = BranchNode->Fallthrough; FlowNode;
          FlowNode = FlowNode->Next)
       CFNs.insert(FlowNode);
   }
 
-  for (const auto &FlowNode : OrphanedNodes)
+  for (auto &FlowNode : OrphanedNodes) {
+    while (FlowNode) {
       CFNs.insert(FlowNode);
+      FlowNode = FlowNode->Next;
+    }
+  }
 
   for (const auto &Node : CFNs)
     delete Node;
 
   for (const auto &Node : CBNs)
     delete Node;
 }