Incorrect DFG edges for tuples used when iterating over a list/set/dict comprehension

[KuechA]

The DFG edges for tuples used as variables used when iterating over a list/set/dict comprehension are incorrect. Currently, the variables/references which hold the values flow into the tuple but it should be the opposite direction. Example:

[foo(k, v) for (k, v) in x]

I'd expect a flow from x to the tuple (InitializerListExpression) and then, an indexed flow to k and v respectively and from there to the References k and v used as arguments of foo.

This issue is a bit related to #1957 but even when fixing #1957, this issue would remain.

[oxisto]

Can we fix both of that in the same PRs? Seems related

[KuechA]

That's my goal. However, I think we should figure out if there are more places and/or a generalized way where we have to turn around the DFG edges between a node n and its children based on n.astParent and also in which cases checking a single layer of the astParent won't be sufficient.