Merge #20674: fuzz: Call SendMessages after ProcessMessage to increase coverage

fa09f97 fuzz: Call SendMessages after ProcessMessage to increase coverage (MarcoFalke)

Pull request description:

ACKs for top commit:
  practicalswift:
    Tested ACK fa09f97
  dhruv:
    tACK fa09f97
  Crypt-iQ:
    cr ACK fa09f97
  sipa:
    utACK fa09f97

Tree-SHA512: 87c52aa38f902c4f6c9c2380f486a3ab21edc0e21e48bb619cdb67cfd698154cc57b170eef31fc940c0bb2c878e155847de03fc6e4cd85bed25f10c4f80c747b

Author: fanquake

src/test/fuzz/process_message.cpp

@@ -75,6 +75,10 @@ void fuzz_target(const std::vector<uint8_t>& buffer, const std::string& LIMIT_TO
                                                 GetTime<std::chrono::microseconds>(), std::atomic<bool>{false});
     } catch (const std::ios_base::failure&) {
     }
+    {
+        LOCK(p2p_node.cs_sendProcessing);
+        g_setup->m_node.peerman->SendMessages(&p2p_node);
+    }
     SyncWithValidationInterfaceQueue();
     LOCK2(::cs_main, g_cs_orphans); // See init.cpp for rationale for implicit locking order requirement
     g_setup->m_node.connman->StopNodes();

src/test/fuzz/process_messages.cpp

@@ -79,6 +79,10 @@ FUZZ_TARGET_INIT(process_messages, initialize_process_messages)
             connman.ProcessMessagesOnce(random_node);
         } catch (const std::ios_base::failure&) {
         }
+        {
+            LOCK(random_node.cs_sendProcessing);
+            g_setup->m_node.peerman->SendMessages(&random_node);
+        }
     }
     SyncWithValidationInterfaceQueue();
     LOCK2(::cs_main, g_cs_orphans); // See init.cpp for rationale for implicit locking order requirement