Randomize second half of above_row_ in intrapred tests for Neon
The existing tests duplicate `above_row_[block_size - 1]` after the
first `block_size` elements, which can lead to tests incorrectly passing
due to differing behaviour when calculating the average for the last
elements of the output.
This change adjusts the above array setup to be fully random instead,
allowing us to catch such issues here rather than in other larger tests
like the external MD5 tests.
It doesn't appear that other architectures are fully clean with this
change so restrict it to just Neon for now until they are fixed.
Bug: webm:1797
Change-Id: If83ff1adbf1e8d30f2a92474d7186c65840a5d0b
1 file changed
