Log GENERAL_LOG after txnStartTS is set

[b6g]

Enhancement

A GENERAL_LOG message is logged before runStmt()

	logStmt(stmt, s)

	var recordSet sqlexec.RecordSet
	if stmt.PsStmt != nil { // point plan short path
		recordSet, err = stmt.PointGet(ctx)
		s.txn.changeToInvalid()
	} else {
		recordSet, err = runStmt(ctx, s, stmt)
	}

So the txnStartTS in a GENERAL_LOG message is usually 0, unless the statement is inside a transaction.

Can we defer logStmt, so that txnStartTS is set and logged, to make the GENERAL_LOG messages more useful?