Replace stdio.h and stdarg.h with C++ versions

src/V3EmitV.cpp

@@ -20,10 +20,10 @@
 
 #include "config_build.h"
 #include "verilatedos.h"
-#include <stdio.h>
-#include <stdarg.h>
+#include <cstdio>
+#include <cstdarg>
 #include <unistd.h>
-#include <math.h>
+#include <cmath>
 #include <map>
 #include <vector>
 #include <algorithm>