Most of these functions have become unusued due to Crankshaft's removal, so
delete them.

Bug: 
Change-Id: If4724c78a0b5c7b6179b22eb4068acd95dfdd29e
Reviewed-on: https://chromium-review.googlesource.com/571011Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Martyn Capewell <martyn.capewell@arm.com>
Cr-Commit-Position: refs/heads/master@{#46699}