The syntax of the CALL statement, to invoke a stored procedure, has been
changed to make the use of parenthesis optional in the argument list.
With this change, "CALL p;" is equivalent to "CALL p();".

While the SQL spec does not explicitely mandate this syntax, supporting it
is needed for practical reasons, for integration with JDBC / ODBC connectors.

Also, warnings in the sql/sql_yacc.yy file, which were not reported by Bison 2.1
but are now reported by Bison 2.2, have been fixed.

The warning found were:
bison -y -p MYSQL  -d --debug --verbose sql_yacc.yy
sql_yacc.yy:653.9-18: warning: symbol UNLOCK_SYM redeclared
sql_yacc.yy:656.9-17: warning: symbol UNTIL_SYM redeclared
sql_yacc.yy:658.9-18: warning: symbol UPDATE_SYM redeclared
sql_yacc.yy:5169.11-5174.11: warning: unused value: $2
sql_yacc.yy:5208.11-5220.11: warning: unused value: $5
sql_yacc.yy:5221.11-5234.11: warning: unused value: $5
conflicts: 249 shift/reduce

"unused value: $2" correspond to the $$=$1 assignment in the 1st {} block
in table_ref -> join_table {} {},
which does not procude a result ($$) for the rule but an intermediate $2
value for the action instead.
"unused value: $5" are similar, with $$ assignments in {} actions blocks
which are not for the final reduce.


mysql-test/r/sp.result:
  New test case for Bug#21462
mysql-test/t/sp.test:
  New test case for Bug#21462
sql/sql_yacc.yy:
  "CALL p;" syntax for calling a stored procedure
  Fixed bison 2.2 warnings.