RosAlloc verification.

If enabled, RosAlloc verification checks the allocator internal
metadata and invariants to detect bugs, heap corruptions, and race
conditions. Added runtime options for enabling and disabling
it. Enable it for the debug build.

Bug: 9986565
Bug: 12592026
Change-Id: I923742b87805ae839f1549d78d0d492733da6a58
9 files changed