[wasm] Fix bounds check for zero initial memory.

src/arm64/assembler-arm64.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
@@ skipping 176 matching lines @@
 uint32_t RelocInfo::wasm_memory_size_reference() {
   DCHECK(IsWasmMemorySizeReference(rmode_));
   return Memory::uint32_at(Assembler::target_pointer_address_at(pc_));
 }
 
 Address RelocInfo::wasm_global_reference() {
   DCHECK(IsWasmGlobalReference(rmode_));
   return Memory::Address_at(Assembler::target_pointer_address_at(pc_));
 }
 
+uint8_t RelocInfo::wasm_memtype_size_reference() {
+  DCHECK(IsWasmMemtypeSizeReference(rmode_));
+  return Memory::uint8_at(Assembler::target_pointer_address_at(pc_));
+}
+
 void RelocInfo::unchecked_update_wasm_memory_reference(
     Address address, ICacheFlushMode flush_mode) {
   Assembler::set_target_address_at(isolate_, pc_, host_, address, flush_mode);
 }
 
 void RelocInfo::unchecked_update_wasm_memory_size(uint32_t size,
                                                   ICacheFlushMode flush_mode) {
   Memory::uint32_at(Assembler::target_pointer_address_at(pc_)) = size;
 }
 
@@ skipping 3005 matching lines @@
   movk(scratch, (target_offset >> 32) & 0xFFFF, 32);
   DCHECK((target_offset >> 48) == 0);
   add(rd, rd, scratch);
 }
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_ARM64