Fix more -Wunreachable-code-aggressive instances.

Bug: chromium:1066980
Change-Id: I5c5e34b970a3b7a87abbec23110588518e99f6af
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3036345
Auto-Submit: Peter Kasting <pkasting@chromium.org>
Commit-Queue: Maya Lekova <mslekova@chromium.org>
Reviewed-by: Maya Lekova <mslekova@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75806}

src/compiler/fast-api-calls.cc

@@ -28,7 +28,6 @@ ElementsKind GetTypedArrayElementsKind(CTypeInfo::Type type) {
     case CTypeInfo::Type::kV8Value:
     case CTypeInfo::Type::kApiObject:
       UNREACHABLE();
-      break;
   }
 }
 

src/objects/objects.cc

@@ -5905,7 +5905,6 @@ GlobalDictionary::TryFindPropertyCellForConcurrentLookupIterator(
     CHECK(element.IsPropertyCell(cage_base));
     return PropertyCell::cast(element);
   }
-  return {};
 }
 
 Handle<StringSet> StringSet::New(Isolate* isolate) {