Oh so your problem is that when attempting to dynamically link to the standard library, you're missing out on the dead code elimination you'd get when statically linking. Rust doesn't have a stable ABI anyways, so you can't really share the standard library between programs unless you're really careful.
I'm not sure what embedded space you're referring to, but microcontrollers, in my experience, generally use monolithic binaries. I'm unsure why you'd wish to use dynamic linking in those cases.
