gc.c: add rb_objspace.limit
* gc.c: add rb_objspace.limit to keep accurate count of total heap slots [ruby-core:57633] [Bug #8983]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@43138 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
gc.c: add rb_objspace.limit
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@43138 b2dd03c8-39d4-4d8f-98ff-823fe69b080e