Prototype of MPS Interpreter Framework based on GraalVM / Truffle

• Required patched version of MPS: https://github.com/enikao/MPS
• Legacy Interpreter docs: http://mbeddr.com/interpreter/Interpreter.html
• GraalVM / Truffle: http://www.graalvm.org/

Hints:

• We need to "Clean Compiled Java Files" on example.mps.com.oracle.truffle.sl.interpreter after every restart of MPS and before every rebuild, to make sure the annotation processors are executed.
• TruffleRuntime will look for its languages only on first invocation. Therefore, every change to the interpreter requires a MPS restart.