Bug#33970 Test main.csv_alter_table disabled.

Re-enabling this test in 5.1 tree since the bug that caused disabling
(Bug#33696 CSV storage engine allows nullable colums via ALTER TABLE statements)
doesn't appear in 5.1 (6.0 only)

Recorded .result file and removed test from the main.disabled.def file.

mysql-test/r/csv_alter_table.result

+# ===== csv_alter_table.1 =====
+DROP TABLE IF EXISTS t1;
+CREATE TABLE t1 (a int NOT NULL) ENGINE = CSV;
+ALTER TABLE t1 ADD COLUMN b CHAR(5) NOT NULL;
+DESC t1;
+Field	Type	Null	Key	Default	Extra
+a	int(11)	NO		NULL	
+b	char(5)	NO		NULL	
+ALTER TABLE t1 DROP COLUMN b;
+DESC t1;
+Field	Type	Null	Key	Default	Extra
+a	int(11)	NO		NULL	
+ALTER TABLE t1 MODIFY a BIGINT NOT NULL;
+DESC t1;
+Field	Type	Null	Key	Default	Extra
+a	bigint(20)	NO		NULL	
+ALTER TABLE t1 CHANGE a a INT NOT NULL;
+DESC t1;
+Field	Type	Null	Key	Default	Extra
+a	int(11)	NO		NULL	
+DROP TABLE t1;
+# ===== csv_alter_table.2 =====
+DROP TABLE IF EXISTS t1;
+CREATE TABLE t1 (a int NOT NULL) ENGINE = CSV;
+ALTER TABLE t1 ADD COLUMN b CHAR(5);
+ERROR 42000: The storage engine for the table doesn't support nullable columns
+DESC t1;
+Field	Type	Null	Key	Default	Extra
+a	int(11)	NO		NULL	
+ALTER TABLE t1 MODIFY a BIGINT;
+ERROR 42000: The storage engine for the table doesn't support nullable columns
+DESC t1;
+Field	Type	Null	Key	Default	Extra
+a	int(11)	NO		NULL	
+ALTER TABLE t1 CHANGE a a INT;
+ERROR 42000: The storage engine for the table doesn't support nullable columns
+DESC t1;
+Field	Type	Null	Key	Default	Extra
+a	int(11)	NO		NULL	
+DROP TABLE t1;

mysql-test/t/disabled.def

@@ -10,6 +10,5 @@
 #
 ##############################################################################
 federated_transactions   : Bug#29523 Transactions do not work
-csv_alter_table      : Bug#33696 2008-01-21 pcrews no .result file - bug allows NULL columns in CSV tables
 log_tables.test                       : Bug #37798: main.log_tables fails randomly on powermacg5 and windows
 slow_query_log_func.test              : Bug #37962: *_func tests containing sleeps/race conditions