Remove empty directory.

The directory was added in rL292747 which was reverted again in 292751 --
but the revert was apparently done via git and the empty dir stuck around in
svn.


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@367838 91177308-0d34-0410-b5e6-96231b3b80d8