gc.c: fix no lazy sweep mode
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@48150 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
gc.c: fix no lazy sweep mode
lazy sweep is enabled or not. based on the patch by Masahiro
Ide at [ruby-dev:48706]. [Bug #10431]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@48150 b2dd03c8-39d4-4d8f-98ff-823fe69b080e