Handle missing Solaris auxv entries

Handle missing Solaris auxv entries

Currently, three tests FAIL on Solaris 11.4+ (amd64-pc-solaris2.11 and
sparcv9-sun-solaris2.11):

info auxv
[...]
2009 AT_SUN_HWCAP         Machine-dependent CPU capability hints 0x3f5ff7
2023 ???                                                 0x0
0    AT_NULL              End of vector                  0x0
(gdb) WARNING: Unrecognized tag value: 2023 ???  0x0

FAIL: gdb.base/auxv.exp: info auxv on live process

info auxv
4294969310 ???                                                 0x7fffbfffe410
9225589753816 ???                                                 0x7fffbfffe45c
[...]
WARNING: Unrecognized tag value: 4294969310 ???  0x7fffbfffe410

WARNING: Unrecognized tag value: 9225589753816 ???  0x7fffbfffe45c

WARNING: Unrecognized tag value: 140733193388037 ???  0x6
[...]
2009 AT_SUN_HWCAP         Machine-dependent CPU capability hints 0x3f5ff7
2023 ???                                                 0x0
0    AT_NULL              End of vector                  0x0
(gdb) WARNING: Unrecognized tag value: 2023 ???  0x0

UNRESOLVED: gdb.base/auxv.exp: info auxv on native core dump

info auxv
[...]
2009 AT_SUN_HWCAP         Machine-dependent CPU capability hints 0x3f5ff7
2023 ???                                                 0x0
0    AT_NULL              End of vector                  0x0
(gdb) WARNING: Unrecognized tag value: 2023 ???  0x0

FAIL: gdb.base/auxv.exp: info auxv on gcore-created dump

The following patch fixes this by introducing the missing AT_SUN_*
values from Solaris 11.4+ <sys/auxv.h>.  This lets the live and
gcore-created dump tests PASS.

I don't know yet what's the reason for those weird 'Unrecognized tag
value' warnings with native core dumps is; elfdump -n certainly doesn't
show them.  However, native core dumps still need quite some work
(mostly in bfd) in this and other areas.

Tested on amd64-pc-solaris2.11.

	gdb:
	* auxv.c (default_print_auxv_entry): Reflect AT_SUN_CAP_HW1
	renaming.
	Handle AT_SUN_EMULATOR, AT_SUN_BRANDNAME, AT_SUN_BRAND_AUX1,
	AT_SUN_BRAND_AUX2, AT_SUN_BRAND_AUX3, AT_SUN_CAP_HW2.

	include:
	* elf/common.h (AT_SUN_HWCAP): Rename to ...
	(AT_SUN_CAP_HW1): ... this.  Retain old name for backward
	compatibility.
	(AT_SUN_EMULATOR, AT_SUN_BRANDNAME, AT_SUN_BRAND_AUX1)
	(AT_SUN_BRAND_AUX2, AT_SUN_BRAND_AUX3, AT_SUN_CAP_HW2): Define.