[Wasm] Move data segment data inline to the data segment section

src/wasm/encoder.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 "src/signature.h"
 
 #include "src/handles.h"
 #include "src/v8.h"
 #include "src/zone-containers.h"
 
@@ skipping 351 matching lines @@
 }
 
 
 uint32_t WasmDataSegmentEncoder::BodySize() const {
   return static_cast<uint32_t>(data_.size());
 }
 
 
 void WasmDataSegmentEncoder::Serialize(byte* buffer, byte** header,
                                        byte** body) const {
-  uint32_t body_offset = static_cast<uint32_t>(*body - buffer);
-  EmitUint32(header, dest_);
-  EmitUint32(header, body_offset);
-  EmitUint32(header, static_cast<uint32_t>(data_.size()));
-  EmitUint8(header, 1);  // init
+  EmitVarInt(header, dest_);
+  EmitVarInt(header, static_cast<uint32_t>(data_.size()));
 
-  std::memcpy(*body, &data_[0], data_.size());
-  (*body) += data_.size();
+  std::memcpy(*header, &data_[0], data_.size());
+  (*header) += data_.size();
 }
 
 WasmModuleBuilder::WasmModuleBuilder(Zone* zone)
     : zone_(zone),
       signatures_(zone),
       functions_(zone),
       data_segments_(zone),
       indirect_functions_(zone),
       globals_(zone),
       signature_map_(zone),
@@ skipping 253 matching lines @@
       next = next | 0x80;
     }
     output.push_back(next);
     shift += 7;
   } while ((next & 0x80) != 0);
   return output;
 }
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8