[D-runtime] Possible critical deadlock issue for 2.049

[Steve Schveighoffer]

Have people seen these?

http://www.digitalmars.com/webnews/newsgroups.php?art_group=digitalmars.D&article_id=117650

http://d.puremagic.com/issues/show_bug.cgi?id=4890

This might need an emergency release... seems like a really bad one.

-Steve