[RFC] Introduce bytecode compilation for Starlarky

[mahmoudimus]

Problem or feature statement

There is demand for the introduction of a "compilation" phase for Larky. The following two features are the most requested:

• Compilation of a Larky script to check for syntax errors without executing it.
• Compilation of a Larky script for later invocation without re-interpreting it.

Advised solution

Ideally leverage the JVM's invokedynamic instruction to have fast dynamic dispatching via JVM bytecode. Or, introduce a Dalvik-like register-based VM built on top of the JVM.

Testing scenarios

TBD

[aslepakurov]

Already introduced in VGS implementation of Larky. Would be good to groom for Larky engine.