Code blocks in cross-crate inlined docs duplicated without formatting

e.g. http://doc.rust-lang.org/std/rt/mutex/struct.NativeMutex.html#method.lock vs http://doc.rust-lang.org/rustrt/mutex/struct.NativeMutex.html#method.lock
