Assertion in RenderTreeBuilder::attachToRenderElementInternal

Assertion in RenderTreeBuilder::attachToRenderElementInternal
https://bugs.webkit.org/show_bug.cgi?id=239823
<rdar://92390285>

Reviewed by Alan Bujtas.

* LayoutTests/fast/css/display-content-with-pending-stylesheet-crash-expected.txt: Added.
* LayoutTests/fast/css/display-content-with-pending-stylesheet-crash.html: Added.
* Source/WebCore/style/StyleTreeResolver.cpp:
(WebCore::Style::TreeResolver::resolveElement):

We can't skip resolution for elements that we have already computed style for. This includes elements with display:contents.

link: https://commits.webkit.org/251178@main
git-svn-id: http://svn.webkit.org/repository/webkit/trunk@295083 268f45cc-cd09-0410-ab3c-d52691b4dbfc