fix C<i $obj> where $obj is a lexical

fix C<i $obj> where $obj is a lexical

the DB::eval function depends on the special behaviour of eval ""
within the DB package, which evaluates the string within the context
of the first non-DB sub or eval scope, working up the call stack.

The debugger refactor moved handling for the 'i' command from the
DB package to the DB::Obj package, so the eval in DB::eval was
working in the context of the DB::Obj::cmd_i function, not in the
calling scope.

Fixed by moving the handling for the i command back to DB.

Fixes #17661.