x86: conditionalize code for ARM neon optimization
x86: conditionalize code for ARM neon optimization

Conditionalize code for ARM neon optimizations so that other architectures
compile correctly.

Change-Id: I538b937734f3e6a3b318e40fcc45579bfa899f28
Signed-off-by: Chet Kener <4bada73e411a9c678a318a79d04d7df4a5fc4429@gmail.com>

wildermason/external_skia,wildermason/external_skia,wildermason/external_skia,wildermason/external_skia,wildermason/external_skia,wildermason/external_skia,wildermason/external_skia,wildermason/external_skia