ART: More header cleanup - CC

Forward-declare AtomicStack in CC. Use stack_reference in atomic_stack.h.

Test: mmma art
Change-Id: I863ca8d4a8dfd5e83279fd68ea0e1a94c3c5df6d
(cherry picked from commit 291ce17ada5a126be99f0fc069a028d2100bcf9e)
3 files changed