[libfuzzer] adding license headers to cpp files

Differential Revision: http://reviews.llvm.org/D18705

llvm-svn: 265174
diff --git a/llvm/lib/Fuzzer/test/LeakTest.cpp b/llvm/lib/Fuzzer/test/LeakTest.cpp
index 7d153e4..69ff10b 100644
--- a/llvm/lib/Fuzzer/test/LeakTest.cpp
+++ b/llvm/lib/Fuzzer/test/LeakTest.cpp
@@ -1,3 +1,6 @@
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+
 // Test with a leak.
 #include <cstdint>
 #include <cstddef>