Purge non-NEON ARM code. DO NOT MERGE

As I begin to wade in here, it's nice to remove as much code as possible.

BUG=skia:4117

Review URL: https://codereview.chromium.org/1277953002

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Cherry-pick of https://skia.googlesource.com/skia/+/e683e810

Speculative fix for b/23648740. Remove the function that crashes.

BUG:23648740
Change-Id: Ie4d681976bc1e39ed4f78d63d30259c9e35aea07
3 files changed