Optimistically ignore scattered relocations in MachO in RuntimeDyld. This
un-breaks simple use cases while I work on more general support.

<rdar://problem/14487667>



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188044 91177308-0d34-0410-b5e6-96231b3b80d8