Applying long outstanding patch.

See:http://thread.gmane.org/gmane.comp.lib.boost.devel/118863/focus=118912


[SVN r36920]

libs/thread

@@ -1 +1 @@
-Subproject commit 6355a5b28df41725c0c77116f6d5a93ae576a192
+Subproject commit d75fb2deda44a63aab094c64c2aab4528a5e0758