[CHORE] Fix YUIDoc parse warnings

[bantic]

When developing locally, there are many YUIDoc warnings that say "Missing item type", like so:

WARNING:  ember-table/-private/utils/array.js:4: Missing item type
Genericizes `objectAt` so it can be run against a normal array or an Ember array
WARNING:  ember-table/-private/utils/array.js:32: Missing item type
Cycle shift an internal [start..end] to [start + 1...end, start].
WARNING:  ember-table/-private/utils/sort.js:32: Missing item type
An implementation of the standard merge sort algorithm.

These can generally be fixed by doing some combination of the following:

• add a @class YUIDoc annotation in the file
• add @property + @type annotations as needed, or
• add @method + @param annotations as needed