rustc-ap-rustc_cratesio_shim 339.0.0

Automatically published version of the package `rustc_cratesio_shim` in the rust-lang/rust repository from commit 6ecad338381cc3b8d56e2df22e5971a598eddd6c The publishing script for this crate lives at: https://github.com/alexcrichton/rustc-auto-publish