Layout 2020: Float Metabug

[mrobinson]

This is a metabug for tracking open issues related to implementation of float in Layout 2020.

Implementation:

• Layout 2020: Implement preferred widths for floats #29874
• Layout 2020: Add support for flowing inlines around floating elements #29825

Bugs:

• Don't pass float stacking containers up to parent stacking contexts #29880
• Layout 2020: Correct rendering of floated root #29870
• Layout 2020: Absolutely positioned elements with a static position are not properly positioned in floats #29826
• Layout 2020: Floats don't take into account that parent may get some margin collapse from children #29886
• Layout 2020: Element with clearance shouldn't be pushed downwards by collapsed margin from child #29885
• Layout 2020: CSS clear not working properly on elements with no height #29884
• Layout 2020: Block formatting context with floats should be big enough to contain their floating content #29823

[mrobinson]

I'm going to close this issue in favor of the a new Layout 2020 Floats project: https://github.com/orgs/servo/projects/7