MDEV-34388/MDEV-36701: mysql status_info_cb disable varargs warnings

Clang complains that the callback is using a variadic based on an enum.

client/mysql.cc:3207:16: error: passing an object that undergoes default argument promotion to 'va_start' has undefined behavior [-Werror,-Wvarargs]
 3207 |   va_start(ap, type);

This is part of the C/C API this has been referred as bug:
* CONC-789 MARIADB_OPT_STATUS_CALLBACK Variadic around enums is undefined behaviour

In the mean time, we are just disabling the warning.

Reviewer: Jimmy Hu <jimmy.hu@mariadb.com>

Author: grooverdan

client/mysql.cc

@@ -3199,6 +3199,12 @@ static int reconnect(void)
 }
 
 #ifndef EMBEDDED_LIBRARY
+#ifdef __clang__
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wvarargs"
+/* CONC-789 */
+#endif
+
 static void status_info_cb(void *data, enum enum_mariadb_status_info type, ...)
 {
   va_list ap;
@@ -3214,6 +3220,10 @@ static void status_info_cb(void *data, enum enum_mariadb_status_info type, ...)
   }
   va_end(ap);
 }
+
+#ifdef __clang__
+#pragma clang diagnostic pop
+#endif
 #else
 #define mysql_optionsv(A,B,C,D) do { } while(0)
 #endif