[LFC] Float prev/next sibling should prevent top/bottom margin collapsing with parent.

[LFC] Float prev/next sibling should prevent top/bottom margin collapsing with parent.
https://bugs.webkit.org/show_bug.cgi?id=188487

Reviewed by Antti Koivisto.

Source/WebCore:

Test: fast/block/block-only/floating-and-next-previous-inflow-with-margin.html

* layout/blockformatting/BlockMarginCollapse.cpp:
(WebCore::Layout::isMarginTopCollapsedWithParent):
(WebCore::Layout::BlockFormattingContext::MarginCollapse::isMarginBottomCollapsedWithParent):

Tools:

* LayoutReloaded/misc/LFC-passing-tests.txt:

LayoutTests:

* fast/block/block-only/floating-and-next-previous-inflow-with-margin-expected.txt: Added.
* fast/block/block-only/floating-and-next-previous-inflow-with-margin.html: Added.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@234786 268f45cc-cd09-0410-ab3c-d52691b4dbfc