[wasm] Remove dangerous ByteArray::data accessor.

R=titzer@chromium.org

Review-Url: https://codereview.chromium.org/2388303008
Cr-Commit-Position: refs/heads/master@{#40028}

src/objects-inl.h

@@ -4059,10 +4059,6 @@ byte ByteArray::get(int index) {
   return READ_BYTE_FIELD(this, kHeaderSize + index * kCharSize);
 }
 
-const byte* ByteArray::data() const {
-  return reinterpret_cast<const byte*>(FIELD_ADDR_CONST(this, kHeaderSize));
-}
-
 void ByteArray::set(int index, byte value) {
   DCHECK(index >= 0 && index < this->length());
   WRITE_BYTE_FIELD(this, kHeaderSize + index * kCharSize, value);

src/objects.h

@@ -4726,7 +4726,6 @@ class ByteArray: public FixedArrayBase {
   // Setter and getter.
   inline byte get(int index);
   inline void set(int index, byte value);
-  inline const byte* data() const;
 
   // Copy in / copy out whole byte slices.
   inline void copy_out(int index, byte* buffer, int length);

src/wasm/wasm-module.cc

@@ -514,8 +514,8 @@ Handle<Code> CompileImportWrapper(Isolate* isolate,
           ByteArray::cast(func->GetInternalField(kInternalSignature)));
       if (exported_param_count == param_count &&
           exportedSig->length() == sig_data->length() &&
-          memcmp(exportedSig->data(), sig_data->data(),
-                 exportedSig->length()) == 0) {
+          memcmp(exportedSig->GetDataStartAddress(),
+                 sig_data->GetDataStartAddress(), exportedSig->length()) == 0) {
         isMatch = true;
       }
     }
@@ -540,7 +540,7 @@ Handle<Code> CompileImportWrapper(Isolate* isolate,
     Zone zone(isolate->allocator());
     MachineRepresentation* reps =
         zone.NewArray<MachineRepresentation>(sig_data_size);
-    memcpy(reps, sig_data->data(),
+    memcpy(reps, sig_data->GetDataStartAddress(),
            sizeof(MachineRepresentation) * sig_data_size);
     FunctionSig sig(ret_count, param_count, reps);