This commit contains all the changes to the recently-imported
Rust code to make it work with our Rust library and pass our
We rename lib.rs to mod.rs to reflect it being a sub-module instead
of a full library. We add this module to our lib.rs. We add various
package dependencies to Cargo.toml. We make a handful of Rust code
updates to reflect the new symbol locations. Finally, we tweak the
Python script generating parser.rs so paths are correct and so
check-code doesn't complain.
As part of adding the dependencies, some versions changed slightly
from the upstream Cargo.toml, as we already had referenced a more
modern crate version.