Re: So 30 years (at least) on ...
"Also itll be interesting to see how they deal with pointers, particularly function pointers and accessing the stack, the sort of low level details other sandboxed languages dont have"
For a useful real world example you can see the implementation of EOS blockchain (https://github.com/EOSIO/eos). The blockchain has a webassembly virtual machine in which the smart contracts run. The smart contracts are written in standard C++17. The compiler is clang 7 that targets wasm (see the SDK: https://github.com/EOSIO/eosio.cdt).