Add an assertion at deletion time to ensure all the transactions were committed.

lib/Interpreter/IncrementalParser.cpp

@@ -130,6 +130,7 @@ namespace cling {
     const Transaction* T = getFirstTransaction();
     const Transaction* nextT = 0;
     while (T) {
+      assert(T->getState() == Transaction::kCommitted && "Not committed?");
       nextT = T->getNext();
       delete T;
       T = nextT;