A clean-up for MDEV-10654 add support IN, OUT, INOUT parameter qualifiers for stored functions

Changes:

1. Enabling IN/OUT/INOUT mode for sql_mode=DEFAULT,
   adding tests for sql_mode=DEFAULT based by mostly
   translating compat/oracle.sp-inout.test to SQL/PSM
   with minor changes (e.g. testing trigger OLD.column and
   NEW.column as IN/OUT parameters).

2. Removing duplicate grammar:
   sp_pdparam and sp_fdparam implemented exactly the same syntax after
   - the first patch for MDEV-10654 (for sql_mode=ORACLE)
   - the change #1 from this patch (for sql_mode=DEFAULT)
   Removing separate rules and adding a single "sp_param" rule instead,
   which now covers both PRDEDURE and FUNCTION parameters
   (and CURSOR parameters as well!).

3. Adding a helper rule sp_param_name_and_mode, which is a combination
   of the parameter name and the IN/OUT/INOUT mode. It allows to simplify
   the grammer a bit.

4. The first patch unintentionally allowed IN/OUT/INOUT mode
  to be specified in CURSOR parameters.
  This is good for the IN keyword - it is allowed in PL/SQL CURSORs.
  This is not good the the OUT/INOUT keywords - they should not be allowed.
  Adding a additional symantic post-check.

1 files changed, 40 insertions, 0 deletions

diff --git a/mysql-test/main/sp-cursor.result b/mysql-test/main/sp-cursor.result
index 110ae7be03a..dc38ad64069 100644
--- a/mysql-test/main/sp-cursor.result
+++ b/mysql-test/main/sp-cursor.result
@@ -737,3 +737,43 @@ rec.en1
 c
 DROP PROCEDURE p1;
 DROP TABLE t1;
+#
+# Start of 10.8 tests
+#
+#
+# MDEV-10654 IN, OUT, INOUT parameters in CREATE FUNCTION
+#
+BEGIN NOT ATOMIC
+DECLARE va INT;
+DECLARE cur CURSOR (IN a INT) FOR SELECT a FROM dual;
+OPEN cur(1);
+FETCH cur INTO va;
+CLOSE cur;
+SELECT va;
+END;
+$$
+va
+1
+BEGIN NOT ATOMIC
+DECLARE va INT;
+DECLARE cur CURSOR (OUT a INT) FOR SELECT a FROM dual;
+OPEN cur(1);
+FETCH cur INTO va;
+CLOSE cur;
+SELECT va;
+END;
+$$
+ERROR 42000: This version of MariaDB doesn't yet support 'OUT/INOUT cursor parameter'
+BEGIN NOT ATOMIC
+DECLARE va INT;
+DECLARE cur CURSOR (INOUT a INT) FOR SELECT a FROM dual;
+OPEN cur(1);
+FETCH cur INTO va;
+CLOSE cur;
+SELECT va;
+END;
+$$
+ERROR 42000: This version of MariaDB doesn't yet support 'OUT/INOUT cursor parameter'
+#
+# End of 10.8 tests
+#