Support several new ELF auxiliary vector types on FreeBSD.

FreeBSD's kernel recently added several ELF auxiliary vector entries
to describe the arguments passed to new executable images during
exec().  The AT_FREEBSD_ARGC and AT_FREEBSD_ARGV entries give the
length and address of the process argument array.  AT_FREEBSD_ENVC and
AT_FREEBSD_ENVV entries give the length and address of the initial
process environment.  AT_FREEBSD_PS_STRINGS gives the address of the
'struct ps_strings' object.

include/ChangeLog:

	* elf/common.h (AT_FREEBSD_ARGC, AT_FREEBSD_ARGV, AT_FREEBSD_ENVC)
	(AT_FREEBSD_ENVV, AT_FREEBSD_PS_STRINGS): Define.

gdb/ChangeLog:

	* fbsd-tdep.c (fbsd_print_auxv_entry): Handle AT_FREEBSD_ARGC,
	AT_FREEBSD_ARGV, AT_FREEBSD_ENVC, AT_FREEBSD_ENVV,
	AT_FREEBSD_PS_STRINGS.

gdb/ChangeLog

@@ -1,3 +1,9 @@
+2020-07-09  John Baldwin  <jhb@FreeBSD.org>
+
+	* fbsd-tdep.c (fbsd_print_auxv_entry): Handle AT_FREEBSD_ARGC,
+	AT_FREEBSD_ARGV, AT_FREEBSD_ENVC, AT_FREEBSD_ENVV,
+	AT_FREEBSD_PS_STRINGS.
+
 2020-07-08  Hannes Domani  <ssbssa@yahoo.de>
 
 	* auto-load.c (auto_load_objfile_script_1): Convert drive part

gdb/fbsd-tdep.c

@@ -1598,6 +1598,11 @@ fbsd_print_auxv_entry (struct gdbarch *gdbarch, struct ui_file *file,
       TAG (HWCAP, _("Machine-dependent CPU capability hints"), AUXV_FORMAT_HEX);
       TAG (HWCAP2, _("Extension of AT_HWCAP"), AUXV_FORMAT_HEX);
       TAG (BSDFLAGS, _("ELF BSD flags"), AUXV_FORMAT_HEX);
+      TAG (ARGC, _("Argument count"), AUXV_FORMAT_DEC);
+      TAG (ARGV, _("Argument vector"), AUXV_FORMAT_HEX);
+      TAG (ENVC, _("Environment count"), AUXV_FORMAT_DEC);
+      TAG (ENVV, _("Environment vector"), AUXV_FORMAT_HEX);
+      TAG (PS_STRINGS, _("Pointer to ps_strings"), AUXV_FORMAT_HEX);
     }
 
   fprint_auxv_entry (file, name, description, format, type, val);

include/ChangeLog

@@ -1,3 +1,8 @@
+2020-07-09  John Baldwin  <jhb@FreeBSD.org>
+
+	* elf/common.h (AT_FREEBSD_ARGC, AT_FREEBSD_ARGV, AT_FREEBSD_ENVC)
+	(AT_FREEBSD_ENVV, AT_FREEBSD_PS_STRINGS): Define.
+
 2020-07-09  Alan Modra  <amodra@gmail.com>
 
 	* coff/powerpc.h: Delete.

include/elf/common.h

@@ -1255,6 +1255,11 @@
 #define AT_FREEBSD_HWCAP        25      /* CPU feature flags. */
 #define AT_FREEBSD_HWCAP2       26      /* CPU feature flags 2. */
 #define AT_FREEBSD_BSDFLAGS     27      /* ELF BSD Flags. */
+#define AT_FREEBSD_ARGC         28      /* Argument count. */
+#define AT_FREEBSD_ARGV         29      /* Argument vector. */
+#define AT_FREEBSD_ENVC         30      /* Environment count. */
+#define AT_FREEBSD_ENVV         31      /* Environment vvector. */
+#define AT_FREEBSD_PS_STRINGS   32      /* struct ps_strings. */
 
 #define AT_SUN_UID      2000    /* Effective user ID.  */
 #define AT_SUN_RUID     2001    /* Real user ID.  */