[wasm] Local decl parsing tweak.

test/unittests/wasm/ast-decoder-unittest.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 "test/unittests/test-utils.h"
 
 #include "src/v8.h"
 
 #include "test/cctest/wasm/test-signatures.h"
 
@@ skipping 2228 matching lines @@
     LocalType type = kLocalTypes[i];
     const byte data[] = {
         1, 1, static_cast<byte>(WasmOpcodes::LocalTypeCodeFor(type))};
     AstLocalDecls decls(zone());
     bool result = DecodeLocalDecls(decls, data, data + sizeof(data));
     EXPECT_TRUE(result);
     EXPECT_EQ(1, decls.total_local_count);
 
     LocalTypeMap map = Expand(decls);
     EXPECT_EQ(1, map.size());
-    EXPECT_EQ(type, map.at(0));
+    EXPECT_EQ(type, map[0]);
   }
 }
 
 TEST_F(LocalDeclDecoderTest, FiveLocals) {
   for (size_t i = 0; i < arraysize(kLocalTypes); i++) {
     LocalType type = kLocalTypes[i];
     const byte data[] = {
         1, 5, static_cast<byte>(WasmOpcodes::LocalTypeCodeFor(type))};
     AstLocalDecls decls(zone());
     bool result = DecodeLocalDecls(decls, data, data + sizeof(data));
@@ skipping 53 matching lines @@
   size_t pos = 0;
   pos = ExpectRun(map, pos, kAstF32, 5);
   pos = ExpectRun(map, pos, kAstI32, 1337);
   pos = ExpectRun(map, pos, kAstI64, 212);
   delete[] data;
 }
 
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8