[dev.regabi] cmd/compile: clean up debug flag (-d) handling [generated]
The debug table is not as haphazard as flags, but there are still
a few mismatches between command-line names and variable names.
This CL moves them all into a consistent home (var Debug, like var Flag).
Code updated automatically using the rf command below.
A followup CL will make a few manual cleanups, leaving this CL
completely automated and easier to regenerate during merge
conflicts.