Avoid NSGetSizeAndAlignment bug

Avoid NSGetSizeAndAlignment bug

Leopard has a bug in the NSGetSizeAndAlignment() function which prevents it
from handling structs which have bitfields in them. This in turn breaks the
+[NSValue valueWithBytes:objCType:] method when used with structs containing
bitfields.

So this commit #ifdefs out the tests which fail as a result of this bug. A
simplified testcase demonstrating the problem has be en added to the "other"
subdirectory. A Radar has been filed (<rdar://problem/5357040>); currently
awaiting on a fix from Apple.

Signed-off-by: Wincent Colaiuta <win@wincent.com>