Dirty elements whose selectors are affected by sibling changes

This fixes incremental layout of nodes that match pseudo-class selectors such
as :first-child, :nth-child, :last-child, :first-of-type, etc.

* Fixes #8191
* Fixes #9063
* Fixes #9303
* Fixes #9448

This code is based on the following flags from Gecko:
https://hg.mozilla.org/mozilla-central/file/e1cf617a1f28/dom/base/nsINode.h#l134

tests/wpt/metadata-css/css-transforms-1_dev/html/transform-stacking-003.htm.ini

@@ -1,3 +0,0 @@
-[transform-stacking-003.htm]
-  type: reftest
-  disabled: https://github.com/servo/servo/issues/9303

tests/wpt/metadata-css/css-transforms-1_dev/html/transform-stacking-004.htm.ini

@@ -1,3 +0,0 @@
-[transform-stacking-004.htm]
-  type: reftest
-  disabled: https://github.com/servo/servo/issues/9448