Update this module to reflect POSIX 2008:
With pathconf, we can avoid calling utimens.
With utimensat, the system resolution can be 1.
With lutimens, we can determine resolution on symlinks.
* lib/utimecmp.c (utimecmp): Use new interface. Skip effort of
hashing when possible. Use pathconf when available.
(SYSCALL_RESOLUTION): Recognize tighter resolution.
* modules/utimecmp (Depends-on): Add lstat.