The LOAD_RAW and LOAD_RAW_NODE_OFFSET macros just call method on the
GraphAssembler now, hence we can remove the macros and just do the calls
directly. This reduces code complexity.

R=jkummerow@chromium.org, tebbi@chromium.org

Bug: v8:10123
Change-Id: I1d779969a14a52256eecb33007564eb190bdcff2
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2039051
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#66149}