tracing: Tracepoint for connected blocks

Can, for example, be used to benchmark block connections.

src/validation.cpp

@@ -48,6 +48,7 @@
 #include <util/rbf.h>
 #include <util/strencodings.h>
 #include <util/system.h>
+#include <util/trace.h>
 #include <util/translation.h>
 #include <validationinterface.h>
 #include <warnings.h>
@@ -1997,6 +1998,16 @@ bool CChainState::ConnectBlock(const CBlock& block, BlockValidationState& state,
     int64_t nTime6 = GetTimeMicros(); nTimeCallbacks += nTime6 - nTime5;
     LogPrint(BCLog::BENCH, "    - Callbacks: %.2fms [%.2fs (%.2fms/blk)]\n", MILLI * (nTime6 - nTime5), nTimeCallbacks * MICRO, nTimeCallbacks * MILLI / nBlocksTotal);
 
+    TRACE7(validation, block_connected,
+        block.GetHash().ToString().c_str(),
+        pindex->nHeight,
+        block.vtx.size(),
+        nInputs,
+        nSigOpsCost,
+        GetTimeMicros() - nTimeStart, // in microseconds (µs)
+        block.GetHash().data()
+    );
+
     return true;
 }