no description for ELF DT_FLAGS

On some builds, we see checker errors of this form:

Dynamic Tag 0x1e unknown

This value is DT_FLAGS:

#define DT_FLAGS 30 /* Flags for the object being loaded */

LSB needs to know something about this tag, so appchk/pkgchk can figure
out what to say, not just report it as unknown.

While looking in the DB, there seem to be a number of dynamic tags
which have a value of '0'. Presumably this means something (perhaps,
Not in LSB?) but I don't recall, so just wanted to check that this is
indeed as intended, for example:

INSERT INTO `DynamicEntries` VALUES (24,'DT_JMPREL','23');
INSERT INTO `DynamicEntries` VALUES (25,'DT_BIND_NOW','0');
INSERT INTO `DynamicEntries` VALUES (26,'DT_INIT_ARRAY','0');
INSERT INTO `DynamicEntries` VALUES (27,'DT_FINI_ARRAY','0');
INSERT INTO `DynamicEntries` VALUES (28,'DT_INIT_ARRAYSZ','0');
INSERT INTO `DynamicEntries` VALUES (29,'DT_FINI_ARRAYSZ','0');
INSERT INTO `DynamicEntries` VALUES (30,'DT_NUM','0');

BIND_NOW to FINI_ARRAYSZ have values '24'-'29', DT_RUNPATH is
defined correctly to '0x1d' (although I'd prefer the value '29'
to stay consistent in naming style.

In a current elf.h header we see:

#define DT_ENCODING 32 /* Start of encoded range */
#define DT_PREINIT_ARRAY 32 /* Array with addresses of preinit
fct*/
#define DT_PREINIT_ARRAYSZ 33 /* size in bytes of DT_PREINIT_ARRAY */
#define DT_NUM 34 /* Number used */

So besides DT_FLAGS, there are three other current dynamic tags
that we don't have any information for in the DB.

I have not checked the higher ranges to any depth but there are
clearly tags there we also know nothing about, such as:

#define DT_GNU_PRELINKED 0x6ffffdf5 /* Prelinking timestamp */
#define DT_GNU_CONFLICTSZ 0x6ffffdf6 /* Size of conflict section */
#define DT_GNU_LIBLISTSZ 0x6ffffdf7 /* Size of library list */

Seems like this needs some examination, as usual there's concern when
we report about unknown tags and it would be good to catch up as much
as possible.