[proxies] Implement [[PreventExtensions]] and [[IsExtensible]].

test/cctest/interpreter/test-bytecode-generator.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.
 
 // TODO(rmcilroy): Remove this define after this flag is turned on globally
 #define V8_IMMINENT_DEPRECATION_WARNINGS
 
 #include "src/v8.h"
 
 #include "src/compiler.h"
@@ skipping 4477 matching lines @@
         helper.MakeBytecodeForFunction(snippets[i].code_snippet);
     CheckBytecodeArrayEqual(snippets[i], bytecode_array);
   }
 }
 
 
 TEST(IllegalRedeclaration) {
   InitializedHandleScope handle_scope;
   BytecodeGeneratorHelper helper;
 
-  ExpectedSnippet<const char*> snippets[] = {
+  CHECK_GE(MessageTemplate::kVarRedeclaration, 128);
+  // Must adapt bytecode if this changes.
+
+  ExpectedSnippet<Handle<Object>, 2> snippets[] = {
       {"const a = 1; { var a = 2; }",
        3 * kPointerSize,
        1,
        14,
        {
-           B(LdaSmi8), U8(MessageTemplate::kVarRedeclaration),          //
+           B(LdaConstant), U8(0),                                       //
            B(Star), R(1),                                               //
-           B(LdaConstant), U8(0),                                       //
+           B(LdaConstant), U8(1),                                       //
            B(Star), R(2),                                               //
            B(CallRuntime), U16(Runtime::kNewSyntaxError), R(1), U8(2),  //
            B(Throw),                                                    //
        },
-       1,
-       {"a"}},
+       2,
+       {helper.factory()->NewNumberFromInt(MessageTemplate::kVarRedeclaration),
+        helper.factory()->NewStringFromAsciiChecked("a")}},
   };
 
   for (size_t i = 0; i < arraysize(snippets); i++) {
     Handle<BytecodeArray> bytecode_array =
         helper.MakeBytecodeForFunctionBody(snippets[i].code_snippet);
     CheckBytecodeArrayEqual(snippets[i], bytecode_array);
   }
 }
 
 
@@ skipping 956 matching lines @@
   for (size_t i = 0; i < arraysize(snippets); i++) {
     Handle<BytecodeArray> bytecode_array =
         helper.MakeBytecodeForFunctionBody(snippets[i].code_snippet);
     CheckBytecodeArrayEqual(snippets[i], bytecode_array);
   }
 }
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8