Since we can just use the lower bits, we can make the compressions no-ops.
As a note, they still change the representation so that the machine graph
verifier is happy.

X64's version of: https://chromium-review.googlesource.com/c/v8/v8/+/1751722

Bug: v8:7703
Change-Id: I728eb8b6b3953f053a7042797f3c498d13e3c948
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1751729Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Commit-Queue: Santiago Aboy Solanes <solanes@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63202}