[maglev] Weaken DCHECK on Double field load

Double-representation field loads were DCHECKing that the entry in the
descriptor array for a double-representation IC is also double
representation. With in-place map updates, however, the IC may be out of
date, so weaken this DCHECK to take into account in-place updates, and
rely on compilation dependency commit making this lookup safe.

Bug: v8:7700
Change-Id: Iff3c80d396274d14034e010dbe98f5640c9e4495
Fixed: chromium:1358872
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3892692
Commit-Queue: Jakob Linke <jgruber@chromium.org>
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Auto-Submit: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Jakob Linke <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/main@{#83166}

src/maglev/maglev-graph-builder.cc

@@ -1040,7 +1040,8 @@ bool MaglevGraphBuilder::TryBuildMonomorphicLoadFromSmiHandler(
     InternalIndex index =
         descriptors.Search(field.property_index(), *map.object());
     DCHECK(index.is_found());
-    DCHECK(descriptors.GetDetails(index).representation().IsDouble());
+    DCHECK(Representation::Double().CanBeInPlaceChangedTo(
+        descriptors.GetDetails(index).representation()));
     const compiler::CompilationDependency* dep =
         broker()->dependencies()->FieldRepresentationDependencyOffTheRecord(
             map, index, Representation::Double());