Direct copy of sse2. Slight improvement because neon has
abs().
flower.ppm had minimal improvement. Somewhat expected because
GetResidualCost_C is only ~3.6%
mug.ppm had a better improvement because GetResidualCost_C is
almost 9%.
C 2.150
NEON 2.130
BUG=b/118740850
Change-Id: Ibc0dd97a81596635f5599cf568205974b4fd2597
Much faster with aarch64. Still somewhat faster without vmaxv.
C: 3.700s
ArmV7: 3.675
aarch64: 3.600
BUG=b/118740850
Change-Id: I3be852da89633eca4bddce443c87f5e4a2f55868
