Add Sdext (External debug arch)

[dhower-qc]

Describe the data

Need to add Sdext to the database. Also need IDL with "builtin" interface to interact with an external debugger model.

[sonalyadav1]

I would like to work on this issue

[ThinkOpenly]

Some of this is done (PR #350), some of this is pending merge (#614). Some is going to be pretty challenging:

Also need IDL with "builtin" interface to interact with an external debugger model.

Not saying "no", but there might be lower-hanging fruit which would be a better "good first issue". (And we might want to remove that tag from this issue, frankly.)

[sonalyadav1]

Are there any easier tasks or ‘good first issues’ you recommend for someone new to the project?

[ThinkOpenly]

Are there any easier tasks or ‘good first issues’ you recommend for someone new to the project?

Perhaps #223?

[ThinkOpenly]

The work here should also include defining the dret instruction.