[libFuzzer] #include <string_view>, hopefully should fix the windows build  

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk/lib/fuzzer@360715 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/FuzzerDataFlowTrace.cpp b/FuzzerDataFlowTrace.cpp
index bfcdf00..9f15cb8 100644
--- a/FuzzerDataFlowTrace.cpp
+++ b/FuzzerDataFlowTrace.cpp
@@ -22,6 +22,7 @@
 #include <queue>
 #include <sstream>
 #include <string>
+#include <string_view>
 #include <unordered_map>
 #include <unordered_set>
 #include <vector>