Add Antithesis intrumentation (#5042)

* Copy Antithesis SDK version 0.4.0 to directory external/
* Add build option `voidstar` to enable instrumentation with Antithesis SDK
* Define instrumentation macros ASSERT and UNREACHABLE in terms of regular C assert
* Replace asserts with named ASSERT or UNREACHABLE
* Add UNREACHABLE to LogicError
* Document instrumentation macros in CONTRIBUTING.md

include/xrpl/server/detail/BaseHTTPPeer.h

@@ -22,6 +22,7 @@
 
 #include <xrpl/basics/Log.h>
 #include <xrpl/beast/net/IPAddressConversion.h>
+#include <xrpl/beast/utility/instrumentation.h>
 #include <xrpl/server/Session.h>
 #include <xrpl/server/detail/io_list.h>
 #include <boost/asio/ip/tcp.hpp>
@@ -34,7 +35,6 @@
 #include <boost/beast/http/parser.hpp>
 #include <boost/beast/http/read.hpp>
 #include <atomic>
-#include <cassert>
 #include <chrono>
 #include <functional>
 #include <memory>

include/xrpl/server/detail/BasePeer.h

@@ -21,12 +21,12 @@
 #define RIPPLE_SERVER_BASEPEER_H_INCLUDED
 
 #include <xrpl/beast/utility/WrappedSink.h>
+#include <xrpl/beast/utility/instrumentation.h>
 #include <xrpl/server/Port.h>
 #include <xrpl/server/detail/LowestLayer.h>
 #include <xrpl/server/detail/io_list.h>
 #include <boost/asio.hpp>
 #include <atomic>
-#include <cassert>
 #include <functional>
 #include <string>
 

include/xrpl/server/detail/BaseWSPeer.h

@@ -21,17 +21,21 @@
 #define RIPPLE_SERVER_BASEWSPEER_H_INCLUDED
 
 #include <xrpl/basics/safe_cast.h>
+#include <xrpl/beast/utility/instrumentation.h>
 #include <xrpl/beast/utility/rngfill.h>
 #include <xrpl/crypto/csprng.h>
 #include <xrpl/protocol/BuildInfo.h>
+#include <xrpl/server/WSSession.h>
 #include <xrpl/server/detail/BasePeer.h>
 #include <xrpl/server/detail/LowestLayer.h>
+
 #include <boost/beast/core/multi_buffer.hpp>
 #include <boost/beast/http/message.hpp>
 #include <boost/beast/websocket.hpp>
+#include <boost/logic/tribool.hpp>
 
-#include <cassert>
 #include <functional>
+#include <list>
 
 namespace ripple {
 
@@ -508,7 +512,9 @@ template <class String>
 void
 BaseWSPeer<Handler, Impl>::fail(error_code ec, String const& what)
 {
-    assert(strand_.running_in_this_thread());
+    ASSERT(
+        strand_.running_in_this_thread(),
+        "ripple::BaseWSPeer::fail : strand in this thread");
 
     cancel_timer();
     if (!ec_ && ec != boost::asio::error::operation_aborted)