Bug 48344: Defer separator constraints to list

Bug 48344 was fixed by I479cfc12f49a5e0f28e92217a9ed041fc2e82223 when
selective serialization is enabled. Without selective serialization, the
constraints set by the inner list items overrule the special handling of the
EOF case for ul.

This patch fixes this issue and a bunch of constraint merge conflict warnings
by deferring the constraint decision from the last list item to the wrapping
list. This avoids forcing a trailing newline even with selective serialization
disabled.

Bug: 48344
Change-Id: Ic20036747f6582741df7e416162029e80b106d8b
Merge "Bug 48344: Defer separator constraints to list"