* gc.c (heap_set_increment): accept minumum additional page number.
* gc.c (gc_after_sweep): allocate pages to allocate at least
   RUBY_HEAP_MIN_SLOTS.
   [Bug #9137]



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@43795 b2dd03c8-39d4-4d8f-98ff-823fe69b080e