[libFuzzer] add an experimental search heuristic flag -reduce_depth

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk/lib/fuzzer@319571 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/FuzzerDriver.cpp b/FuzzerDriver.cpp
index 6480fbe..83f796d 100644
--- a/FuzzerDriver.cpp
+++ b/FuzzerDriver.cpp
@@ -566,6 +566,7 @@
   Options.MaxTotalTimeSec = Flags.max_total_time;
   Options.DoCrossOver = Flags.cross_over;
   Options.MutateDepth = Flags.mutate_depth;
+  Options.ReduceDepth = Flags.reduce_depth;
   Options.UseCounters = Flags.use_counters;
   Options.UseIndirCalls = Flags.use_indir_calls;
   Options.UseMemmem = Flags.use_memmem;