[wasm] Introduce Encoder::GetLocal and Encoder::SetLocal utilities.

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 132 matching lines @@
 }
 
 
 void WasmFunctionBuilder::ReturnType(LocalType type) { return_type_ = type; }
 
 
 void WasmFunctionBuilder::EmitCode(const byte* code, uint32_t code_size) {
   EmitCode(code, code_size, nullptr, 0);
 }
 
+void WasmFunctionBuilder::EmitGetLocal(uint32_t local_index) {
+  local_indices_.push_back(static_cast<uint32_t>(body_.size() + 1));
+  EmitWithVarInt(kExprGetLocal, local_index);
+}
+
+void WasmFunctionBuilder::EmitSetLocal(uint32_t local_index) {
+  local_indices_.push_back(static_cast<uint32_t>(body_.size() + 1));
+  EmitWithVarInt(kExprSetLocal, local_index);
+}
 
 void WasmFunctionBuilder::EmitCode(const byte* code, uint32_t code_size,
                                    const uint32_t* local_indices,
                                    uint32_t indices_size) {
   size_t size = body_.size();
   for (size_t i = 0; i < code_size; i++) {
     body_.push_back(code[i]);
   }
   for (size_t i = 0; i < indices_size; i++) {
     local_indices_.push_back(local_indices[i] + static_cast<uint32_t>(size));
@@ skipping 567 matching lines @@
       next = next | 0x80;
     }
     output.push_back(next);
     shift += 7;
   } while ((next & 0x80) != 0);
   return output;
 }
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8