bugfix: lnnvl raw expr printer

tools/deploy/mysql_test/test_suite/static_engine/r/mysql/expr_lnnvl.result

@@ -35,3 +35,26 @@ select lnnvl('abc') from dual;
 |            1 |
 +--------------+
 
+drop view if exists v1;
+create view v1 as select lnnvl(1) from dual;
+show create view v1;
+View	Create View	character_set_client	collation_connection
+v1	CREATE VIEW `v1` AS select lnnvl(1) AS `lnnvl(1)`	utf8mb4	utf8mb4_general_ci
+explain select * from v1;
+Query Plan
+==========================================
+|ID|OPERATOR  |NAME|EST.ROWS|EST.TIME(us)|
+------------------------------------------
+|0 |EXPRESSION|    |1       |1           |
+==========================================
+Outputs & filters:
+-------------------------------------
+  0 - output([lnnvl(cast(1, TINYINT(-1, 0)))]), filter(nil)
+      values({lnnvl(cast(1, TINYINT(-1, 0)))})
+select * from v1;
++----------+
+| lnnvl(1) |
++----------+
+|        0 |
++----------+
+drop view v1;

tools/deploy/mysql_test/test_suite/static_engine/t/expr_lnnvl.test

@@ -19,5 +19,14 @@ select lnnvl(0) from dual;
 select lnnvl(NULL) from dual;
 select lnnvl('abc') from dual;
 
+--disable_warnings
+drop view if exists v1;
+--enable_warnings
+create view v1 as select lnnvl(1) from dual;
+show create view v1;
+explain select * from v1;
+select * from v1;
+drop view v1;
+
 connection syscon;
 --sleep 2