[wasm] Fix bounds check for zero initial memory.

test/cctest/test-run-wasm-relocation-x64.cc

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <stdlib.h>
 
 #include "src/v8.h"
 
 #include "src/debug/debug.h"
 #include "src/disasm.h"
@@ skipping 72 matching lines @@
 TEST(WasmRelocationX64WasmMemorySizeReference) {
   CcTest::InitializeVM();
   Isolate* isolate = CcTest::i_isolate();
   HandleScope scope(isolate);
   v8::internal::byte buffer[4096];
   Assembler assm(isolate, buffer, sizeof buffer);
   DummyStaticFunction(NULL);
   int32_t size = 512;
   Label fail;
 
-  __ movl(rax, Immediate(size, RelocInfo::WASM_MEMORY_SIZE_REFERENCE));
-  __ cmpl(rax, Immediate(size, RelocInfo::WASM_MEMORY_SIZE_REFERENCE));
+  __ movl(rax, Immediate(size, RelocInfo::WASM_MEMORY_DWORD_SIZE_REFERENCE));
+  __ cmpl(rax, Immediate(size, RelocInfo::WASM_MEMORY_DWORD_SIZE_REFERENCE));
   __ j(not_equal, &fail);
   __ ret(0);
   __ bind(&fail);
   __ movl(rax, Immediate(0xdeadbeef));
   __ ret(0);
 
   CodeDesc desc;
   assm.GetCode(&desc);
   Handle<Code> code = isolate->factory()->NewCode(
       desc, Code::ComputeFlags(Code::STUB), Handle<Code>());
   USE(code);
 
   CSignature0<int64_t> csig;
   CodeRunner<int64_t> runnable(isolate, code, &csig);
   int64_t ret_value = runnable.Call();
   CHECK_NE(ret_value, 0xdeadbeef);
 
 #ifdef OBJECT_PRINT
   OFStream os(stdout);
   code->Print(os);
   byte* begin = code->instruction_start();
   byte* end = begin + code->instruction_size();
   disasm::Disassembler::Disassemble(stdout, begin, end);
 #endif
   int32_t diff = 512;
 
-  int mode_mask = (1 << RelocInfo::WASM_MEMORY_SIZE_REFERENCE);
+  int mode_mask = (1 << RelocInfo::WASM_MEMORY_DWORD_SIZE_REFERENCE);
   for (RelocIterator it(*code, mode_mask); !it.done(); it.next()) {
     RelocInfo::Mode mode = it.rinfo()->rmode();
     if (RelocInfo::IsWasmMemorySizeReference(mode)) {
       it.rinfo()->update_wasm_memory_reference(
           reinterpret_cast<Address>(1234), reinterpret_cast<Address>(1234),
           it.rinfo()->wasm_memory_size_reference(),
           it.rinfo()->wasm_memory_size_reference() + diff, SKIP_ICACHE_FLUSH);
     }
   }
 
   ret_value = runnable.Call();
   CHECK_NE(ret_value, 0xdeadbeef);
 
 #ifdef OBJECT_PRINT
   code->Print(os);
   begin = code->instruction_start();
   end = begin + code->instruction_size();
   disasm::Disassembler::Disassemble(stdout, begin, end);
 #endif
 }
 #undef __