This is the second reland of 4683d6fe

Initial CL:   crrev.com/c/2874663
First reland: crrev.com/c/2886861

The first reland fixes Ref construction failures in:
- MapRef::instance_descriptors
- NativeContext reads (see also crrev.com/c/2891575)

The second reland (this CL):
- Adds required infrastructure (e.g. kAssumeMemoryFence) but
  without enabling the IsPendingAllocation check. Enabling the check
  will be done separately to avoid further revert chains.

Original change's description:
> [compiler] Consider IsPendingAllocation in Ref construction
>
> The logic in JSHeapBroker::TryGetOrCreateData assumes that parts
> of the object are safe to read. In particular, the instance type
> must be readable for the chain of `Is##Name()` type checks.
>
> This is guaranteed if
>
>  - a global memory fence happened after object initialization and
>    prior to the read by the compiler; or
>  - the object was published through a release store and read through
>    an acquire read.
>
> The former is protected by the new call to ObjectMayBeUninitialized
> (which internally calls IsPendingAllocation) in TryGetOrCreateData.
>
> The latter must be marked explicitly by calling the new
> MakeRefAssumeMemoryFence variant.
>
> Note that support in this CL is expected to be incomplete and will
> have to be extended in the future as more cases show up in which
> MakeRef calls must be converted to MakeRefAssumeMemoryFence or to
> TryMakeRef.
>
> Bug: v8:7790,v8:11711
> Change-Id: Ic2f7d9fc46e4bfc3f6bbe42816f73fc5ec174337
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2874663
> Commit-Queue: Jakob Gruber <jgruber@chromium.org>
> Reviewed-by: Georg Neis <neis@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#74474}

Bug: v8:7790,v8:11711,chromium:1207680,chromium:1207679
Change-Id: I123b2962df724a13dd2c7334ae949234bc3bf27a
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2902738Reviewed-by: Georg Neis <neis@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#74638}