- Remove unused deoptimization reasons.
- Replace most uses of kNoReason with an actual reason (some are new).
- Rename kNoReason to kUnknown.

Bug: 
Change-Id: Ia8df54fca0f0f4885ef0c3523ce8f67b557a635d
Reviewed-on: https://chromium-review.googlesource.com/839421Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Commit-Queue: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#50440}