Allow using the `rust-lang/rust:nightly` docker image to run tests in cases where the host rust and cargo cannot be used, such as non-linux hosts.
* Expand wasm32 testing on CI Run the full `run.sh` test script to get full assertions, including that nothing in the wasm compiler-builtins is panicking. Unfortunately it's currently panicking, so this is good to weed out! * Update libm