tests: Add ParseHDKeypath(...) (bip32) fuzzing harness

src/test/fuzz/parse_hd_keypath.cpp

@@ -0,0 +1,13 @@
+// Copyright (c) 2009-2019 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <test/fuzz/fuzz.h>
+#include <util/bip32.h>
+
+void test_one_input(const std::vector<uint8_t>& buffer)
+{
+    const std::string keypath_str(buffer.begin(), buffer.end());
+    std::vector<uint32_t> keypath;
+    (void)ParseHDKeypath(keypath_str, keypath);
+}