[libFuzzer] when doing the merge, keep track of the coveraged edges, not just features

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk/lib/fuzzer@354087 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/FuzzerDriver.cpp b/FuzzerDriver.cpp
index 434c481..9f1621f 100644
--- a/FuzzerDriver.cpp
+++ b/FuzzerDriver.cpp
@@ -483,9 +483,9 @@
 
   std::string CFPath = CFPathOrNull ? CFPathOrNull : TempPath(".txt");
   Vector<std::string> NewFiles;
-  Set<uint32_t> NewFeatures;
+  Set<uint32_t> NewFeatures, NewCov;
   CrashResistantMerge(Args, OldCorpus, NewCorpus, &NewFiles, {}, &NewFeatures,
-                      CFPath, true);
+                      {}, &NewCov, CFPath, true);
   for (auto &Path : NewFiles)
     F->WriteToOutputCorpus(FileToVector(Path, Options.MaxLen));
   // We are done, delete the control file if it was a temporary one.