Consumed Analysis: The 'consumable' attribute now takes a identifier specifying the default assumed state for objects of this class

This information is used for return states and pass-by-value parameter
states.

Patch by Chris Wailes.

Review by DeLesley Hutchins and Aaron Ballman.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@190116 91177308-0d34-0410-b5e6-96231b3b80d8