Revert of [cleanup] CodeStubAssembler: s/compiler::Node/Node/ (patchset #1 id:1 of https://codereview.chromium.org/2526803002/ )

Reason for revert:
Needed to revert https://codereview.chromium.org/2522393002/

Original issue's description:
> Reland of [cleanup] CodeStubAssembler: s/compiler::Node/Node/
>
> Reducing visual clutter.
>
> No changes since previous attempt; this was only reverted because it blocked another revert.
> Original review: https://codereview.chromium.org/2519093002/
>
> TBR=ishell@chromium.org
>
> Committed: https://crrev.com/c28bee0fdd297d2ef4fc88b5fe289cc9dbd664f6
> Cr-Commit-Position: refs/heads/master@{#41235}

TBR=ishell@chromium.org,jkummerow@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Review-Url: https://codereview.chromium.org/2529863002
Cr-Commit-Position: refs/heads/master@{#41249}