* 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/fhandler.h

@@ -296,6 +296,7 @@ class fhandler_base
   virtual _off64_t lseek (_off64_t offset, int whence);
   virtual int lock (int, struct __flock64 *);
   virtual int dup (fhandler_base *child);
+  virtual int fpathconf (int);
 
   virtual HANDLE mmap (caddr_t *addr, size_t len, int prot,
 		       int flags, _off64_t off);