• Add cmake hooks to build and run Rust test executables
• Add at least one Rust test executable validating the above and that such executables work as-expected under Shadow.

#762 is a good place to start looking. In particular shows how we could integrate with cmake.

As discovered in that PR, Rust code currently doesn't run correctly under Shadow. This is thought to be an elf-loader bug, so could be resolved by #738.