[wasm] Use kSystemPointerSize to check for alignment

Change-Id: I84d53282278d12c2e47b8e9a07b69ecf89dba237
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2087692
Commit-Queue: Milad Farazmand <miladfar@ca.ibm.com>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#66584}

src/wasm/wasm-serialization.cc

@@ -362,7 +362,9 @@ void NativeModuleSerializer::WriteCode(const WasmCode* code, Writer* writer) {
   // buffer if necessary so we can relocate the serialized code.
   std::unique_ptr<byte[]> aligned_buffer;
   if (!IsAligned(reinterpret_cast<Address>(serialized_code_start),
-                 kInt32Size)) {
+                 kSystemPointerSize)) {
+    // 'byte' does not guarantee an alignment but seems to work well enough in
+    // practice.
     aligned_buffer.reset(new byte[code_size]);
     code_start = aligned_buffer.get();
   }