[wasm] Fix bounds check for zero initial memory.

src/mips/assembler-mips.cc

 // Copyright (c) 1994-2006 Sun Microsystems Inc.
 // 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.
 //
@@ skipping 186 matching lines @@
 Address RelocInfo::wasm_global_reference() {
   DCHECK(IsWasmGlobalReference(rmode_));
   return Assembler::target_address_at(pc_, host_);
 }
 
 uint32_t RelocInfo::wasm_memory_size_reference() {
   DCHECK(IsWasmMemorySizeReference(rmode_));
   return reinterpret_cast<uint32_t>(Assembler::target_address_at(pc_, host_));
 }
 
+uint8_t RelocInfo::wasm_memtype_size_reference() {
+  DCHECK(IsWasmMemtypeSizeReference(rmode_));
+  return static_cast<byte>(
+      reinterpret_cast<uintptr_t>(Assembler::target_address_at(pc_, host_)));
+}
+
 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) {
   Assembler::set_target_address_at(isolate_, pc_, host_,
                                    reinterpret_cast<Address>(size), flush_mode);
 }
@@ skipping 3011 matching lines @@
 
   if (icache_flush_mode != SKIP_ICACHE_FLUSH) {
     Assembler::FlushICache(isolate, pc, 2 * sizeof(int32_t));
   }
 }
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_MIPS