Auto merge of #14461 - heycam:bloom-no-common-ancestor, r=emilio

allow the style bloom filter to recover from switch to a node with no common ancestor with the old node

<!-- Please describe your changes on the following line: -->

Since https://bugzilla.mozilla.org/show_bug.cgi?id=1321284, we can have multiple disjoint subtrees of elements to style in a document, due to document level native anonymous content not inheriting from the document's element.  This patch tweaks the style Bloom filter to allow switching to a new node that has no common ancestor with the old node.

r? @emilio

---
<!-- Thank you for contributing to Servo! Please replace each `[ ]` by `[X]` when the step is complete, and replace `__` with appropriate data: -->
- [ ] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [ ] These changes fix #__ (github issue number if applicable).

<!-- Either: -->
- [ ] There are tests for these changes OR
- [ ] These changes do not require tests because _____

<!-- Pull requests that do not address these steps are welcome, but they will require additional verification as part of the review process. -->

… common ancestor with the old node.

<!-- Reviewable:start -->
---
This change is [<img src="https://reviewable.io/review_button.svg" height="34" align="absmiddle" alt="Reviewable"/>](https://reviewable.io/reviews/servo/servo/14461)
<!-- Reviewable:end -->

0 files changed, 0 insertions, 0 deletions