Revert "Merge https://android.googlesource.com/platform/libcore into jb-devel"

This reverts commit 4255e75812c01f355a3abdcd6b6153e07bd4f52e, reversing
changes made to ac1606c325ae68ca4a8140e29f57fcc6ae9bd4e3.
Revert "Merge https://android.googlesource.com/platform/libcore into jb-devel"

This reverts commit ac1606c325ae68ca4a8140e29f57fcc6ae9bd4e3, reversing
changes made to 5534ccbe8d76a4fb2b87820ba17f421c6ac99735.