Revert "[snapshot] Turn alignment DCHECKS into CHECKS"

This reverts commit 83f60359.

Reason for revert: RB-Dev crash - crbug.com/1338687

Original change's description:
> [snapshot] Turn alignment DCHECKS into CHECKS
>
> This is a temporary change to get more detailed crash reports for
> further investigations.
>
> Bug: chromium:1330861
> Change-Id: Ifdd8d61692577dffd54d07fadb65575a5c30dcd3
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3707592
> Reviewed-by: Leszek Swirski <leszeks@chromium.org>
> Commit-Queue: Camillo Bruni <cbruni@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#81262}

Bug: chromium:1330861, chromium:1338687
Change-Id: I845aee5cfe02dee399851484d1a72f73dc56f1f4
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3718943
Auto-Submit: Sunny Sachanandani <sunnyps@chromium.org>
Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Commit-Queue: Toon Verwaest <verwaest@chromium.org>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Cr-Commit-Position: refs/heads/main@{#81327}

src/snapshot/deserializer.cc

@@ -423,20 +423,6 @@ void Deserializer<IsolateT>::PostProcessNewJSReceiver(
                                     HeapObject::RequiredAlignment(map)));
 }
 
-namespace {
-// TODO(cbruni, 1330861): Remove once we get enough crash data.
-template <typename IsolateT>
-V8_NOINLINE void CheckAlignment(HeapObject raw_obj, Map raw_map,
-                                IsolateT* isolate,
-                                AllocationAlignment alignment, int filler_size,
-                                InstanceType instance_type) {
-  CHECK_EQ(raw_map, raw_obj.map(isolate));
-  CHECK_EQ(0, Heap::GetFillToAlign(raw_obj.address(), alignment));
-  CHECK_EQ(filler_size, 0);
-  CHECK_LE(0, static_cast<int>(instance_type));
-}
-}  // namespace
-
 template <typename IsolateT>
 void Deserializer<IsolateT>::PostProcessNewObject(Handle<Map> map,
                                                   Handle<HeapObject> obj,
@@ -445,18 +431,12 @@ void Deserializer<IsolateT>::PostProcessNewObject(Handle<Map> map,
   Map raw_map = *map;
   DCHECK_EQ(raw_map, obj->map(isolate_));
   InstanceType instance_type = raw_map.instance_type();
-  HeapObject raw_obj = *obj;
 
   // Check alignment.
-  // TODO(cbruni, 1330861): Revert to DCHECK once we know the root cause
-  AllocationAlignment alignment = HeapObject::RequiredAlignment(raw_map);
-  int filler_size = Heap::GetFillToAlign(raw_obj.address(), alignment);
-  if (filler_size != 0) {
-    CheckAlignment(raw_obj, raw_map, isolate_, alignment, filler_size,
-                   raw_map.instance_type());
-  }
+  DCHECK_EQ(0, Heap::GetFillToAlign(obj->address(),
+                                    HeapObject::RequiredAlignment(raw_map)));
+  HeapObject raw_obj = *obj;
   DCHECK_IMPLIES(deserializing_user_code(), should_rehash());
-
   if (should_rehash()) {
     if (InstanceTypeChecker::IsString(instance_type)) {
       // Uninitialize hash field as we need to recompute the hash.