print: try harder to ensure DbgScope parents come before their children.

[eddyb]

Follow-up to:

• print: name and reuse inlined call site debuginfo "scopes". #18

Overlooked an edge case (scope.parent() being in the claimed map, but at a later position than scope itself, i.e. part of the same "claim" batch) in the original PR, now the order is properly "outside-in":

Before	After

[Firestar99]

I honestly don't fully know what the difference between the screenshots are. Just some lines changed :D

[eddyb]

I honestly don't fully know what the difference between the screenshots are

Thanks to the context for each // d123 = ... being printed on the line just before it (think the reverse of a backtrace, so something like main always being first, and going down towards leaf functions), this fix means the d numbers appear monotonically, in a big block like that - more generally, def-before-use should be enforced.

When using the HTML directly (which I should start linking again, if only these files weren't so huge), the effect is that now clicking through these d123 references always brings up "up"/earlier (to smaller numbers, e.g. d123 -> d100 -> d99 -> d20 -> d5 -> d0, for a 6-deep nesting of inlined functions).