bring more O3 optimizations on cpp files

Change-Id: If6ac473700affd1111707132543690c3e4860df0
switch to sabermod androideabi 4.8.5

Change-Id: I637cb17ac3f3d402335ca644effe95de3bc7c875
added -mtune=cortex-a15 to arch variant as clang recognizes this flag

Change-Id: I154b148240307fbc5eb6089522683320e0814e04