Coroutine Debugger support

Java thread stack with coroutine information

1. Real frames
2. Coroutine 'preflight' frame: SuspendExitMode is SUSPEND_LAMBDA or SUSPEND_METHOD_PARAMETER. Location.isPreflight
3. One or more frames (skipped in debugger)
4. Coroutine 'starting' frame: SuspendExitMode SUSPEND_METHOD frame
5. Restored from coroutine information frames
6. Real frames after the 'starting' frame
7. Creation frames (only exists if coroutine agent enabled)

Debugger interface

Debugger works as a combination of PositionManager and AsyncStackTraceProvider. Once the 'preflight' signature frame found PositionManager forms a 'preflight' frame with coroutine information which gets processed with AsyncStackTraceProvider.