Ruby 1.9.3 support

[jmtame]

Would be great to see this updated to support Ruby 1.9.3 =]

[max99x]

Comment copied from original issue on repl.it:

When I looked into it, Ruby 1.9 was too reliant on threads (which are not supported in the browser). We'd need to cut all the threading out manually for it to be viable. There are no immediate plans to support Ruby 1.9, but we'll be happy to include it if someone contributes an implementation.

[malachaifrazier]

Has some implementation of Node.js been taken into consideration?

[nihonjinrxs]

Now that web workers are more available in browser implementations, could you possibly do "threads" via web workers, or do web worker limitations prevent that being feasible?

[max99x]

Web workers do not support sleep()/await() or synchronous messages, so they can't be used to simulate arbitrary threads. However, it's technically possible to emulate them on a single thread with some effort. It's been a while since I looked at Emscripten, but it's possible that it supports that emulation by now.