Implement Java debugger Python API

[michalgr]

Raw JDWP is too verbose for convenient debugging experience. Ideally we would be able to debug Java processes using API consisting of Threads, StackFrames, Variables and Breakpoints that underneath translates all interactions to/from JDWP messages. The API should support two use cases:

• Interactive debugging from Python REPL, for example

  debugger = connect(...)
  event = await debugger.on("void java.lang.Integer.toString()")
  thread = event.thread
  thread.stackTrace
  thread.frame[0].this
  thread.resume()

• Scripting, users specifying set of breakpoints and reactions to breakpoints as standalone python scripts, for example:

  
  debugger = connect(...)

@debugger.on("void java.lang.Integer.toString()") async def callback(event: BreakpointEvent): thread = event.thread println(f"Called toString on ${thread.frame[0].this}") println(thread.stackTrace) event2 = await thread.singleStep() println(thread.stackTrace)

Once completed we should be able to use new API to debug Java processes on host machine, as well as Java processes on Android devices.