Introduce {ConstantElementsPair} struct for type safety.

src/interpreter/bytecode-array-builder.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_INTERPRETER_BYTECODE_ARRAY_BUILDER_H_
 #define V8_INTERPRETER_BYTECODE_ARRAY_BUILDER_H_
 
 #include "src/ast/ast.h"
 #include "src/base/compiler-specific.h"
 #include "src/globals.h"
@@ skipping 170 matching lines @@
   // with the |object| in a register and the closure in the accumulator.
   BytecodeArrayBuilder& CreateWithContext(Register object,
                                           Handle<ScopeInfo> scope_info);
 
   // Create a new arguments object in the accumulator.
   BytecodeArrayBuilder& CreateArguments(CreateArgumentsType type);
 
   // Literals creation.  Constant elements should be in the accumulator.
   BytecodeArrayBuilder& CreateRegExpLiteral(Handle<String> pattern,
                                             int literal_index, int flags);
-  BytecodeArrayBuilder& CreateArrayLiteral(Handle<FixedArray> constant_elements,
-                                           int literal_index, int flags);
+  BytecodeArrayBuilder& CreateArrayLiteral(
+      Handle<ConstantElementsPair> constant_elements, int literal_index,
+      int flags);
   BytecodeArrayBuilder& CreateObjectLiteral(
       Handle<FixedArray> constant_properties, int literal_index, int flags,
       Register output);
 
   // Push the context in accumulator as the new context, and store in register
   // |context|.
   BytecodeArrayBuilder& PushContext(Register context);
 
   // Pop the current context and replace with |context|.
   BytecodeArrayBuilder& PopContext(Register context);
@@ skipping 228 matching lines @@
   static int const kNoFeedbackSlot = 0;
 
   DISALLOW_COPY_AND_ASSIGN(BytecodeArrayBuilder);
 };
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_INTERPRETER_BYTECODE_ARRAY_BUILDER_H_