* gc.c, internal.h: add new internal memory mangement functions.
* void *ruby_xsizedrealloc(void *ptr, size_t new_size, size_t old_size)
* void ruby_xsizedfree(void *x, size_t size)
  These functions acccept additional size parameter to calculate more
  accurate malloc_increase parameter which control GC timing.
  [Feature #8985]



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@43330 b2dd03c8-39d4-4d8f-98ff-823fe69b080e