Update concept of node filter algorithm
Implement new [filter](https://dom.spec.whatwg.org/#concept-node-filter) algorithm from specification
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- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [X] These changes fix#18218 (github issue number if applicable).
- [X] These changes do not require tests because changes are minimal and the error was triggered by a test
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Add iterpath and iterdir to CSS test runner.
This allows running a subset of the CSS tests again, by specifying
a directory or single test.
Fixes#18931.
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Fix duplicate stacking context creation for anonymous Flows
Anonymous nodes were previously creating duplicate stacking contexts,
one for each node in the anonymous node chain. This change eliminates
that for tables.
Additionally the use of stacking context ids based on node addresses is
no longer necessary since stacking contexts no longer control scrolling.
This is the first step in eliminating the dependency between node
addresses and ClipScrollNodes which causes issues like #16425.
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Anonymous nodes were previously creating duplicate stacking contexts,
one for each node in the anonymous node chain. This change eliminates
that for tables.
Additionally the use of stacking context ids based on node addresses is
no longer necessary since stacking contexts no longer control scrolling.
This is the first step in eliminating the dependency between node
addresses and ClipScrollNodes which causes issues like #16425.
