RosAlloc fast path inline in assembly for x86 32bit.

Port patch https://android-review.googlesource.com/#/c/180014/ for
x86 32bit.
Measurement:
AndroidGCTest(ms, the lower the better): 73372->68165, 7.10% improvement.

Signed-off-by: lwang85 <li.w.wang@intel.com>
Change-Id: I9ac3fc56f98574c41fc070dbf12ce7474d6a3610
1 file changed