Remove rust-0.12.0-libdir.patch from rust-9999.

Signed-off-by: OGINO Masanori <masanori.ogino@gmail.com>
Merge pull request #35 from omasanori/libdir-master

Remove rust-0.12.0-libdir.patch from rust-9999.
[dev-lang/rust] do not apply rust-0.12.0-libdir.patch to nightly rust as it is merged to upstream now
[dev-lang/rust,dev-lang/rust-bin,app-admin/eselect-rust] handle rust-lldb symlink
[app-admin/eselect-rust] fix manifest
[dev-lang/rust,dev-lang/rust-bin] add note for user about LLDB
[dev-lang/rust-bin] fix note for user about LLDB