* fhandler.cc (check_posix_perm): Moved here from syscalls.cc.

(fhandler_base::fpathconf): New method implementing (f)pathconf.
	* fhandler.h (class fhandler_base): Declare fpathconf method.
	* path.cc (path_conv::check): Replace MAX_LINK_DEPTH with SYMLOOP_MAX.
	* path.h (MAX_LINK_DEPTH): Delete.
	* syscalls.cc (check_posix_perm): Move to fhandler.cc.
	(fpathconf): Call fhandler's fpathconf method.
	(pathconf): Build fhandler and call fhandler's fpathconf method.
	* sysconf.cc (sysconf): Reorder switch according to order of flags
	in sys/unistd.h.  Add handling for some missing flags.
	* include/limits.h: Reorder according to SUSv3 description.  Add some
	missing definitions.  Add comments.
	* include/sys/syslimits.h: New file overriding newlib's syslimits.h
	file.

winsup/cygwin/path.cc

@@ -907,7 +907,7 @@ virtual_component_retry:
 	}
 
       /* Arrive here if above loop detected a symlink. */
-      if (++loop > MAX_LINK_DEPTH)
+      if (++loop > SYMLOOP_MAX)
 	{
 	  error = ELOOP;   // Eep.
 	  return;