* gc.c (heap_page_resurrect): do not return tomb_pages when
page->freelist == NULL.
[Bug #12670]
test for [Bug #12670]
heap corruption by deferred free.
gc.c: expand sorted pages
* gc.c (heap_page_allocate): expand sorted pages before inserting
allocated new page. [Bug #12670]
merge revision(s) 56558,59116,59136: [Backport #12670]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_4@59302 b2dd03c8-39d4-4d8f-98ff-823fe69b080e