Remove deprication from mariadbd --debug

--debug is supported by allmost all our other binaries and we should keep
it also in the server to keep option names similar.

mysql-test/suite/innodb/r/innodb-blob.result

@@ -20,8 +20,6 @@ a	RIGHT(b,20)
 2	bbbbbbbbbbbbbbbbbbbb
 connection default;
 SET DEBUG='+d,row_ins_extern_checkpoint';
-Warnings:
-Warning	1287	'@@debug' is deprecated and will be removed in a future release. Please use '@@debug_dbug' instead
 SET DEBUG_SYNC='before_row_ins_extern_latch SIGNAL rec_not_blob WAIT_FOR crash';
 ROLLBACK;
 BEGIN;
@@ -88,8 +86,6 @@ BEGIN;
 INSERT INTO t2 VALUES (347);
 connection default;
 SET DEBUG='+d,row_upd_extern_checkpoint';
-Warnings:
-Warning	1287	'@@debug' is deprecated and will be removed in a future release. Please use '@@debug_dbug' instead
 SET DEBUG_SYNC='before_row_upd_extern SIGNAL have_latch WAIT_FOR crash';
 UPDATE t3 SET c=REPEAT('i',3000) WHERE a=2;
 connection con2;
@@ -126,8 +122,6 @@ BEGIN;
 INSERT INTO t2 VALUES (33101);
 connection default;
 SET DEBUG='+d,row_upd_extern_checkpoint';
-Warnings:
-Warning	1287	'@@debug' is deprecated and will be removed in a future release. Please use '@@debug_dbug' instead
 SET DEBUG_SYNC='after_row_upd_extern SIGNAL have_latch WAIT_FOR crash';
 UPDATE t3 SET c=REPEAT('j',3000) WHERE a=2;
 connection con2;

mysql-test/suite/innodb/r/innodb-index-debug.result

@@ -88,8 +88,6 @@ ALTER TABLE t1 FORCE, ADD COLUMN k4 int;
 connection default;
 SET DEBUG_SYNC= 'now WAIT_FOR opened';
 SET debug = '+d,row_log_tmpfile_fail';
-Warnings:
-Warning	1287	'@@debug' is deprecated and will be removed in a future release. Please use '@@debug_dbug' instead
 INSERT INTO t1 select NULL,'aaa','bbb' from t480;
 INSERT INTO t1 select NULL,'aaaa','bbbb' from t480;
 SET DEBUG_SYNC= 'now SIGNAL flushed';

mysql-test/suite/innodb/r/innodb-table-online.result

@@ -40,16 +40,10 @@ SET DEBUG_DBUG = '+d,innodb_OOM_prepare_inplace_alter';
 ALTER TABLE t1 ROW_FORMAT=REDUNDANT, ALGORITHM=INPLACE, LOCK=NONE;
 ERROR HY000: Out of memory.
 SET SESSION DEBUG = @saved_debug_dbug;
-Warnings:
-Warning	1287	'@@debug' is deprecated and will be removed in a future release. Please use '@@debug_dbug' instead
 SET SESSION DEBUG = '+d,innodb_OOM_inplace_alter';
-Warnings:
-Warning	1287	'@@debug' is deprecated and will be removed in a future release. Please use '@@debug_dbug' instead
 ALTER TABLE t1 ROW_FORMAT=REDUNDANT, ALGORITHM=INPLACE, LOCK=NONE;
 ERROR HY000: Out of memory.
 SET SESSION DEBUG = @saved_debug_dbug;
-Warnings:
-Warning	1287	'@@debug' is deprecated and will be removed in a future release. Please use '@@debug_dbug' instead
 ALTER TABLE t1 ROW_FORMAT=REDUNDANT, ALGORITHM=INPLACE, LOCK=NONE;
 connection default;
 SHOW CREATE TABLE t1;

mysql-test/suite/innodb/r/page_reorganize.result

@@ -16,8 +16,6 @@ SET @save_dbug = @@debug_dbug;
 SET DEBUG_DBUG = '+d,do_page_reorganize,do_lock_reverse_page_reorganize';
 insert into t1(f2) values (repeat('+', 100));
 SET DEBUG = @save_dbug;
-Warnings:
-Warning	1287	'@@debug' is deprecated and will be removed in a future release. Please use '@@debug_dbug' instead
 commit;
 connection con1;
 f1

mysql-test/suite/innodb_fts/r/ft_result_cache_limit.result

@@ -20,8 +20,6 @@ END//
 CALL populate_t1;
 SET autocommit=1;
 SET SESSION debug="+d,fts_instrument_result_cache_limit";
-Warnings:
-Warning	1287	'@@debug' is deprecated and will be removed in a future release. Please use '@@debug_dbug' instead
 ALTER TABLE t1 ADD FULLTEXT INDEX `text_content_idx` (`text_content`);
 SELECT FTS_DOC_ID, text_content
 FROM t1

mysql-test/suite/innodb_gis/r/check_rtree.result

 create table t1 (i int, g geometry not null, spatial index (g))engine=innodb;
 SET SESSION debug="+d,rtree_test_check_count";
-Warnings:
-Warning	1287	'@@debug' is deprecated and will be removed in a future release. Please use '@@debug_dbug' instead
 insert into t1 values (1, POINT(1,1));
 insert into t1 values (1, POINT(1.5,1.5));
 insert into t1 values (1, POINT(3,3));

mysql-test/suite/innodb_gis/r/rollback.result

@@ -408,8 +408,6 @@ update t1 set a=point(5,5), b=point(5,5), c=5 where i < 3;
 ERROR 23000: Duplicate entry '5' for key 'c'
 rollback;
 set session debug="+d,row_mysql_crash_if_error";
-Warnings:
-Warning	1287	'@@debug' is deprecated and will be removed in a future release. Please use '@@debug_dbug' instead
 update t1 set a=point(5,5), b=point(5,5), c=5 where i < 3;
 ERROR HY000: Lost connection to MySQL server during query
 insert into t1 values(5, point(5,5), point(5,5), 5);

mysql-test/suite/innodb_gis/r/rtree_compress.result

@@ -42,8 +42,6 @@ count(*)
 0
 SET @saved_dbug = @@SESSION.debug_dbug;
 SET DEBUG='+d,page_copy_rec_list_start_compress_fail';
-Warnings:
-Warning	1287	'@@debug' is deprecated and will be removed in a future release. Please use '@@debug_dbug' instead
 delete from t1;
 select count(*) from t1 where MBRWithin(t1.c2, @g1);
 count(*)

mysql-test/suite/innodb_gis/r/rtree_create_inplace.result

@@ -31,7 +31,5 @@ COUNT(*)
 0
 ALTER TABLE t1 DROP INDEX idx, ADD SPATIAL INDEX idx3(c2);
 SET SESSION debug="+d,row_merge_instrument_log_check_flush";
-Warnings:
-Warning	1287	'@@debug' is deprecated and will be removed in a future release. Please use '@@debug_dbug' instead
 ALTER TABLE t1  DROP INDEX idx3, ADD SPATIAL INDEX idx4(c2), ADD SPATIAL INDEX idx5(c3);
 DROP TABLE t1;

mysql-test/suite/rpl/r/rpl_semisync_ali_issues.result

@@ -266,16 +266,12 @@ Variable_name	Value
 Rpl_semi_sync_master_clients	1
 # Test failure of select error .
 SET GLOBAL debug = 'd,rpl_semisync_simulate_select_error';
-Warnings:
-Warning	1287	'@@debug' is deprecated and will be removed in a future release. Please use '@@debug_dbug' instead
 INSERT INTO t1 VALUES(3);
 connection slave;
 connection con1;
 # Test failure of pthread_create
 SET GLOBAL rpl_semi_sync_master_enabled = 0;
 SET GLOBAL debug = 'd,rpl_semisync_simulate_create_thread_failure';
-Warnings:
-Warning	1287	'@@debug' is deprecated and will be removed in a future release. Please use '@@debug_dbug' instead
 SET GLOBAL rpl_semi_sync_master_enabled= ON;
 # Test failure of pthread_join
 SET GLOBAL rpl_semi_sync_master_enabled= OFF;
@@ -283,8 +279,6 @@ SET GLOBAL rpl_semi_sync_master_enabled= OFF;
 # Failure on registering semisync slave
 #
 SET GLOBAL debug= 'd,rpl_semisync_simulate_add_slave_failure';
-Warnings:
-Warning	1287	'@@debug' is deprecated and will be removed in a future release. Please use '@@debug_dbug' instead
 SET GLOBAL rpl_semi_sync_master_enabled= ON;
 connection slave;
 STOP SLAVE IO_THREAD;
@@ -293,8 +287,6 @@ START SLAVE IO_THREAD;
 include/wait_for_slave_io_to_start.inc
 connection con1;
 SET GLOBAL debug='';
-Warnings:
-Warning	1287	'@@debug' is deprecated and will be removed in a future release. Please use '@@debug_dbug' instead
 connection slave;
 START SLAVE IO_THREAD;
 include/wait_for_slave_io_to_start.inc

mysql-test/suite/sys_vars/r/debug_basic.result

 set session debug="L";
-Warnings:
-Warning	1287	'@@debug' is deprecated and will be removed in a future release. Please use '@@debug_dbug' instead
 select @@global.debug="1";
 @@global.debug="1"
 0

mysql-test/suite/sys_vars/r/sysvars_debug.result

@@ -38,7 +38,7 @@ GLOBAL_VALUE_ORIGIN	COMPILE-TIME
 DEFAULT_VALUE	
 VARIABLE_SCOPE	SESSION
 VARIABLE_TYPE	VARCHAR
-VARIABLE_COMMENT	Built-in DBUG debugger
+VARIABLE_COMMENT	Built-in DBUG debugger. Alias for --debug
 NUMERIC_MIN_VALUE	NULL
 NUMERIC_MAX_VALUE	NULL
 NUMERIC_BLOCK_SIZE	NULL

sql/sys_vars.cc

@@ -1002,11 +1002,10 @@ static Sys_var_charptr_fscs Sys_datadir(
 static Sys_var_dbug Sys_dbug(
        "debug", "Built-in DBUG debugger", sys_var::SESSION,
        CMD_LINE(OPT_ARG, '#'), DEFAULT(""), NO_MUTEX_GUARD, NOT_IN_BINLOG,
-       ON_CHECK(check_has_super), ON_UPDATE(0),
-       DEPRECATED("'@@debug_dbug'")); // since 5.5.37
+       ON_CHECK(check_has_super));
 
 static Sys_var_dbug Sys_debug_dbug(
-       "debug_dbug", "Built-in DBUG debugger", sys_var::SESSION,
+       "debug_dbug", "Built-in DBUG debugger. Alias for --debug", sys_var::SESSION,
        CMD_LINE(OPT_ARG, '#'), DEFAULT(""), NO_MUTEX_GUARD, NOT_IN_BINLOG,
        ON_CHECK(check_has_super));
 #endif