Revert of PPC: [compiler] Add relocatable pointer constants for wasm memory references. (patchset #1 id:1 of https://codereview.chromium.org/1851543004/ )

Reason for revert:
Original commit reverted.

Original issue's description:
> PPC: [compiler] Add relocatable pointer constants for wasm memory references.
>
> Port eb5fe0df
>
> Original commit message:
>     Add relocatable pointers for wasm memory references that need to
>     be updated when wasm GrowMemory is used. Code generator changes to
>     accept relocatable constants as immediates.
>
> R=gdeepti@google.com, joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com
> BUG=
>
> Committed: https://crrev.com/ba053c4620c3b91ddc540f733f8b4dd9a792bb13
> Cr-Commit-Position: refs/heads/master@{#35203}

TBR=gdeepti@google.com,joransiu@ca.ibm.com,jyan@ca.ibm.com,michael_dawson@ca.ibm.com
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=

Review URL: https://codereview.chromium.org/1851823002

Cr-Commit-Position: refs/heads/master@{#35210}