Make accessing Debugger registers more ergonomic

[Xyene]

[codecov-commenter]

Codecov Report

Merging #997 (d6c7393) into master (485f264) will increase coverage by 2.92%. The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #997      +/-   ##
==========================================
+ Coverage   81.12%   84.04%   +2.92%     
==========================================
  Files         140      140              
  Lines        4753     4752       -1     
==========================================
+ Hits         3856     3994     +138     
+ Misses        897      758     -139     

Impacted Files	Coverage Δ
dmoj/cptbox/isolate.py	89.50% <100.00%> (+37.35%)	:arrow_up:
dmoj/judge.py	52.83% <0.00%> (+1.25%)	:arrow_up:
dmoj/executors/java_executor.py	85.35% <0.00%> (+2.02%)	:arrow_up:
dmoj/cptbox/compiler_isolate.py	55.31% <0.00%> (+6.38%)	:arrow_up:
dmoj/cptbox/tracer.py	76.32% <0.00%> (+18.02%)	:arrow_up:
dmoj/cptbox/handlers.py	100.00% <0.00%> (+25.00%)	:arrow_up:
dmoj/control.py	100.00% <0.00%> (+64.70%)	:arrow_up:

---

Continue to review full report at Codecov.

Legend - Click here to learn more Δ = absolute <relative> (impact), ø = not affected, ? = missing data Powered by Codecov. Last update 485f264...d6c7393. Read the comment docs.

[Riolku]

Agree on Quantum's comment, otherwise looks good.