fix build with GCC 8.1.0

src/cryptonote_basic/account.cpp

@@ -157,7 +157,7 @@ DISABLE_VS_WARNINGS(4244 4345)
   void account_base::create_from_viewkey(const cryptonote::account_public_address& address, const crypto::secret_key& viewkey)
   {
     crypto::secret_key fake;
-    memset(&fake, 0, sizeof(fake));
+    memset(&unwrap(fake), 0, sizeof(fake));
     create_from_keys(address, fake, viewkey);
   }
   //-----------------------------------------------------------------

src/daemon/rpc_command_executor.cpp

@@ -973,7 +973,7 @@ bool t_rpc_command_executor::print_transaction_pool_stats() {
   }
   else
   {
-    memset(&res.pool_stats, 0, sizeof(res.pool_stats));
+    res.pool_stats = {};
     if (!m_rpc_server->on_get_transaction_pool_stats(req, res, false) || res.status != CORE_RPC_STATUS_OK)
     {
       tools::fail_msg_writer() << make_error(fail_message, res.status);

src/rpc/core_rpc_server_commands_defs.h

@@ -1554,6 +1554,8 @@ namespace cryptonote
     std::vector<txpool_histo> histo;
     uint32_t num_double_spends;
 
+    txpool_stats(): bytes_total(0), bytes_min(0), bytes_max(0), bytes_med(0), fee_total(0), oldest(0), txs_total(0), num_failing(0), num_10m(0), num_not_relayed(0), histo_98pc(0), num_double_spends(0) {}
+
     BEGIN_KV_SERIALIZE_MAP()
       KV_SERIALIZE(bytes_total)
       KV_SERIALIZE(bytes_min)