We used to have two special cases for named accesses on the global
proxy, one based on seeing the global proxy constant in the graph and
on based on seeing the global proxy map either in the feedback or in
the graph. A change I made a while ago accidentally disabled the second
one. This CL restores that.

Moreover, given how things are set up now (this might have been
different before), the first optimization is subsumed by the second
one, so this CL also removes the first one.

Finally, this CL records an accumulator hint in the case of a load,
which improves precision of the serializer for concurrent inlining.

Tbr: tebbi@chromium.org
Bug: v8:7790
Change-Id: I255afc6c79e5c5c900b3ccfcd8459d836d21e42b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1801954
Commit-Queue: Georg Neis <neis@chromium.org>
Reviewed-by: Michael Stanton <mvstanton@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63806}