Setting up OrderIterator shouldn't require an extra Vector

This change reuses the OrderIterator's Vector for fun and profit.
The idea is to have an helper class OrderIteratorPopulator, used for
manipulating the Vector directly.

The helper class has the nice upside of consolidating the code into a
single implementation across flexbox and grid.

Also tweaked the Vector to have an inline capacity for a single entry
that will cover the common case.


Review URL:

git-svn-id: svn:// bbb929c8-8fbe-4397-9dbb-9b2b20218538
5 files changed