Support 'info proc' for native FreeBSD processes.

- Command line arguments are fetched via the kern.proc.args.<pid>
  sysctl.
- The 'cwd' and 'exe' values are obtained from the per-process
  file descriptor table returned by kinfo_getfile() from libutil.
- 'mappings' is implemented by walking the array of VM map entries
  returned by kinfo_getvmmap() from libutil.
- 'status' output is generated by outputting fields from the structure
  returned by the kern.proc.pid.<pid> sysctl.
- 'stat' is aliased to 'status'.

gdb/ChangeLog:

	* configure.ac: Check for kinfo_getfile in libutil.
	* configure: Regenerate.
	* config.in: Regenerate.
	* fbsd-nat.c: Include "fbsd-tdep.h".
	(fbsd_fetch_cmdline): New.
	(fbsd_fetch_kinfo_proc): Move earlier and change to return a bool
	rather than calling error.
	(fbsd_info_proc): New.
	(fbsd_thread_name): Report error if fbsd_fetch_kinfo_proc fails.
	(fbsd_wait): Report warning if fbsd_fetch_kinfo_proc fails.
	(fbsd_nat_add_target): Set "to_info_proc" to "fbsd_info_proc".

gdb/configure

@@ -7927,6 +7927,66 @@ $as_echo "#define HAVE_KINFO_GETVMMAP 1" >>confdefs.h
 fi
 
 
+# fbsd-nat.c can also use kinfo_getfile.
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing kinfo_getfile" >&5
+$as_echo_n "checking for library containing kinfo_getfile... " >&6; }
+if test "${ac_cv_search_kinfo_getfile+set}" = set; then :
+  $as_echo_n "(cached) " >&6
+else
+  ac_func_search_save_LIBS=$LIBS
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
+#ifdef __cplusplus
+extern "C"
+#endif
+char kinfo_getfile ();
+int
+main ()
+{
+return kinfo_getfile ();
+  ;
+  return 0;
+}
+_ACEOF
+for ac_lib in '' util util-freebsd; do
+  if test -z "$ac_lib"; then
+    ac_res="none required"
+  else
+    ac_res=-l$ac_lib
+    LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
+  fi
+  if ac_fn_c_try_link "$LINENO"; then :
+  ac_cv_search_kinfo_getfile=$ac_res
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext
+  if test "${ac_cv_search_kinfo_getfile+set}" = set; then :
+  break
+fi
+done
+if test "${ac_cv_search_kinfo_getfile+set}" = set; then :
+
+else
+  ac_cv_search_kinfo_getfile=no
+fi
+rm conftest.$ac_ext
+LIBS=$ac_func_search_save_LIBS
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_kinfo_getfile" >&5
+$as_echo "$ac_cv_search_kinfo_getfile" >&6; }
+ac_res=$ac_cv_search_kinfo_getfile
+if test "$ac_res" != no; then :
+  test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
+
+$as_echo "#define HAVE_KINFO_GETFILE 1" >>confdefs.h
+
+fi
+
+
 
       if test "X$prefix" = "XNONE"; then
     acl_final_prefix="$ac_default_prefix"