Allow SQLCOM_CALL in prepared mode.

mysql-test/r/ps.result:
  Test results: adding tests for CALL statement in prepared mode.
mysql-test/t/ps.test:
  Adding tests for CALL statement in prepared mode.

mysql-test/r/ps.result

@@ -542,3 +542,31 @@ execute my_stmt;
 COUNT(*)
 37
 deallocate prepare my_stmt;
+drop procedure if exists p1|
+drop table if exists t1|
+create table t1 (id int)|
+insert into t1 values(1)|
+create procedure p1(a int, b int)
+begin
+declare c int;
+select max(id)+1 into c from t1;
+insert into t1 select a+b;
+insert into t1 select a-b;
+insert into t1 select a-c;
+end|
+set @a= 3, @b= 4|
+prepare stmt from "call p1(?, ?)"|
+execute stmt using @a, @b|
+execute stmt using @a, @b|
+select * from t1|
+id
+1
+7
+-1
+1
+7
+-1
+-5
+deallocate prepare stmt|
+drop procedure p1|
+drop table t1|