Minor optimization in membuffer cache:  we allocate space to items at a 16 byte granularity.  Thus, we can replace contents as long as their aligned size does not increase.
Minor optimization in membuffer cache:  we allocate space to items
at a 16 byte granularity.  Thus, we can replace contents as long
as their aligned size does not increase.

* subversion/libsvn_subr/cache-membuffer.c
  (membuffer_cache_set_internal): improve check whether we actually
   need to re-allocate space within the cache

git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@1442056 13f79535-47bb-0310-9956-ffa450edef68

YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion