[wasm] Encode immediates to Load and Store as varint.

src/wasm/encoder.h

 // 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.
 
 #ifndef V8_WASM_ENCODER_H_
 #define V8_WASM_ENCODER_H_
 
 #include "src/signature.h"
 #include "src/zone-containers.h"
 
@@ skipping 37 matching lines @@
 class WasmFunctionBuilder : public ZoneObject {
  public:
   uint16_t AddParam(LocalType type);
   uint16_t AddLocal(LocalType type);
   void ReturnType(LocalType type);
   void EmitCode(const byte* code, uint32_t code_size);
   void EmitCode(const byte* code, uint32_t code_size,
                 const uint32_t* local_indices, uint32_t indices_size);
   void Emit(WasmOpcode opcode);
   void EmitWithU8(WasmOpcode opcode, const byte immediate);
+  void EmitWithU8U8(WasmOpcode opcode, const byte imm1, const byte imm2);
   void EmitWithVarInt(WasmOpcode opcode, uint32_t immediate);
   uint32_t EmitEditableVarIntImmediate();
   void EditVarIntImmediate(uint32_t offset, const uint32_t immediate);
   void Exported(uint8_t flag);
   void External(uint8_t flag);
   void SetName(const unsigned char* name, int name_length);
   WasmFunctionEncoder* Build(Zone* zone, WasmModuleBuilder* mb) const;
 
  private:
   explicit WasmFunctionBuilder(Zone* zone);
@@ skipping 78 matching lines @@
   SignatureMap signature_map_;
   int start_function_index_;
 };
 
 std::vector<uint8_t> UnsignedLEB128From(uint32_t result);
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_WASM_ENCODER_H_