In vp8_sub_pixel_variance8x8_neon the temp2 buffer is only initialized
to kHeight8 * kWidth8. However, in the case that xoffset != 0 and
yoffset == 0, var_filter_block2d_bil_w8 is called with output_width
kHeight8PlusOne.
Thanks to cmugurel for diagnosing and yulius for the patch.
Change-Id: Ib71ffd96ffad963c92b8b7ca23f303942785b8e0
https://code.google.com/p/webrtc/issues/detail?id=4190
Use the right return values - vget_low_s64 returns int64x1_t, not
a normal int64_t.
Also make __builtin_prefetch a no-op on MSVC for this file.
Change-Id: I4d2fce01d0ba106b98d3d53b137803119c2c2c08
