Port 6e90f2f2

Original Commit Message:

    Including but not limiting to removing:
     * BitcastCompressedXXX
     * CheckedCompressedXXX
     * ChangeXXXToCompressedYYY
     * ChangeCompressedXXX

    As a note, ChangeTaggedToCompressed can't be removed just yet as it
    is still in use.

R=solanes@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com
BUG=
LOG=N

Change-Id: I0974b300654f61d152ea65016a0e278ea4ba1b60
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1907440Reviewed-by: Junliang Yan <jyan@ca.ibm.com>
Commit-Queue: Milad Farazmand <miladfar@ca.ibm.com>
Cr-Commit-Position: refs/heads/master@{#64885}