WRT floating-point, worth noting for those who haven't read the patches:

- Kernels generally don't want to use floating-point, because saving and restoring the floating-point registers is fairly expensive. - Without some pretty aggressive hacking, it's not possible to remove floating-point support from Rust. - What you /can/ do (and what these patches do) is replace all the floating-point builtins with kernel panics. - This obviously sucks versus actually removing the floating-point, but this is an RFC.

There is some work in progress to make it easier to tell Cargo to build `core`/`alloc`, which in turn would allow projects to maintain patches atop them like disabling floating-point or oom-panicking APIs entirely. I suspect that this effort will get a great deal of motivation from being a kernel requirement