Follow-up to #197805. Make CommandObject::GetTarget the canonical target
accessor for command code, and tighten its semantics so that DoExecute
methods can't accidentally operate on the dummy target.
GetTarget now returns Target* instead of Target&. The result is the
target from the command's frozen execution context, falling back to the
interpreter's execution context. The dummy target is filtered out and
replaced with nullptr unless the command opts in via one of the
eCommandRequires{Target,Process,Thread,Frame} flags (in which case
CheckRequirements has already guaranteed a real target) or via the new
eCommandAllowsDummyTarget flag.
This is the first half of the cleanup discussed at the end of #197805. A
follow-up will audit DoExecute methods that still reach for
GetSelectedTarget or m_exe_ctx.GetTargetPtr() directly and migrate them
to GetTarget.
Jonas Devlieghere
2474ac009b