Help us test patches to support 32-bit hosts (and other cleanup)

http://groups.google.com/group/android-building/browse_thread/thread/9a582d058e9afc15
32bitでのビルドは捨ててないってこと？

The patches for 32-bit hosts are http://r.android.com/23134 and
http://r.android.com/23135
We're also using the opportunity to clean up some build warnings that
have been causing some confusion: http://r.android.com/23136 and
http://r.android.com/23137