Introduce {ConstantElementsPair} struct for type safety.

test/unittests/interpreter/bytecode-array-builder-unittest.cc

 // Copyright 2014 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/v8.h"
 
 #include "src/interpreter/bytecode-array-builder.h"
 #include "src/interpreter/bytecode-array-iterator.h"
 #include "src/interpreter/bytecode-label.h"
 #include "src/interpreter/bytecode-register-allocator.h"
@@ skipping 107 matching lines @@
   builder.CreateClosure(0, NOT_TENURED);
 
   // Emit create context operation.
   builder.CreateBlockContext(factory->NewScopeInfo(1));
   builder.CreateCatchContext(reg, name, factory->NewScopeInfo(1));
   builder.CreateFunctionContext(1);
   builder.CreateWithContext(reg, factory->NewScopeInfo(1));
 
   // Emit literal creation operations.
   builder.CreateRegExpLiteral(factory->NewStringFromStaticChars("a"), 0, 0)
-      .CreateArrayLiteral(factory->NewFixedArray(1), 0, 0)
+      .CreateArrayLiteral(factory->NewConstantElementsPair(
+                              FAST_ELEMENTS, factory->empty_fixed_array()),
+                          0, 0)
       .CreateObjectLiteral(factory->NewFixedArray(1), 0, 0, reg);
 
   // Call operations.
   builder.Call(reg, reg_list, 1, Call::GLOBAL_CALL)
       .Call(reg, reg_list, 1, Call::NAMED_PROPERTY_CALL,
             TailCallMode::kDisallow)
       .Call(reg, reg_list, 1, Call::GLOBAL_CALL, TailCallMode::kAllow)
       .CallRuntime(Runtime::kIsArray, reg)
       .CallRuntimeForPair(Runtime::kLoadLookupSlotForCall, reg_list, pair)
       .CallJSRuntime(Context::SPREAD_ITERABLE_INDEX, reg_list)
@@ skipping 183 matching lines @@
   // Emit wide load / store lookup slots.
   builder.LoadLookupSlot(wide_name, TypeofMode::NOT_INSIDE_TYPEOF)
       .LoadLookupSlot(wide_name, TypeofMode::INSIDE_TYPEOF)
       .StoreLookupSlot(wide_name, LanguageMode::SLOPPY)
       .StoreLookupSlot(wide_name, LanguageMode::STRICT);
 
   // CreateClosureWide
   builder.CreateClosure(1000, NOT_TENURED);
 
   // Emit wide variant of literal creation operations.
-  builder.CreateRegExpLiteral(factory->NewStringFromStaticChars("wide_literal"),
-                              0, 0)
-      .CreateArrayLiteral(factory->NewFixedArray(2), 0, 0)
+  builder
+      .CreateRegExpLiteral(factory->NewStringFromStaticChars("wide_literal"), 0,
+                           0)
+      .CreateArrayLiteral(factory->NewConstantElementsPair(
+                              FAST_ELEMENTS, factory->empty_fixed_array()),
+                          0, 0)
       .CreateObjectLiteral(factory->NewFixedArray(2), 0, 0, reg);
 
   // Emit load and store operations for module variables.
   builder.LoadModuleVariable(-1, 42)
       .LoadModuleVariable(0, 42)
       .LoadModuleVariable(1, 42)
       .StoreModuleVariable(-1, 42)
       .StoreModuleVariable(0, 42)
       .StoreModuleVariable(1, 42);
 
@@ skipping 398 matching lines @@
     iterator.Advance();
   }
   CHECK_EQ(iterator.current_bytecode(), Bytecode::kReturn);
   iterator.Advance();
   CHECK(iterator.done());
 }
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8