Incorrect results when comparing types.systemSetType against other types

[jycor]

Dolt:

tmp/main> select @@sql_mode;
+---------------------------------------------------------------+
| @@sql_mode                                                    |
+---------------------------------------------------------------+
| NO_ENGINE_SUBSTITUTION,ONLY_FULL_GROUP_BY,STRICT_TRANS_TABLES |
+---------------------------------------------------------------+
1 row in set (0.00 sec)

tmp/main> select @@sql_mode = 0;
+----------------+
| @@sql_mode = 0 |
+----------------+
| false          |
+----------------+
1 row in set (0.00 sec)

tmp/main> select @@sql_mode = 'asd';
value asd was not found in the set

MySQL:

mysql> select @@sql_mode;
+---------------------------------------------------------------+
| @@sql_mode                                                    |
+---------------------------------------------------------------+
| ONLY_FULL_GROUP_BY,STRICT_TRANS_TABLES,NO_ENGINE_SUBSTITUTION |
+---------------------------------------------------------------+
1 row in set (0.0005 sec)

mysql> select @@sql_mode = 0;
+----------------+
| @@sql_mode = 0 |
+----------------+
|              1 |
+----------------+
1 row in set, 1 warning (0.0006 sec)
Warning (code 1292): Truncated incorrect DOUBLE value: 'ONLY_FULL_GROUP_BY,STRICT_TRANS_TABLES,NO_ENGINE_SUBSTITUTION'

mysql> select @@sql_mode = 'asd';
+--------------------+
| @@sql_mode = 'asd' |
+--------------------+
|                  0 |
+--------------------+
1 row in set (0.0015 sec)

Related: dolthub/go-mysql-server#2842