Rosalloc thread local allocation path without a cas.

Speedup on N4:
MemAllocTest 3044 -> 2396 (~21% reduction)
BinaryTrees  4101 -> 2929 (~26% reduction)

Bug: 9986565
Change-Id: Ia1d1a37b9e001f903c3c056e8ec68fc8c623a78b
35 files changed