[cleanup] Remove dead code for handling pre-desugaring spread implementation

src/full-codegen/x64/full-codegen-x64.cc

 // Copyright 2012 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.
 
 #if V8_TARGET_ARCH_X64
 
 #include "src/full-codegen/full-codegen.h"
 #include "src/ast/compile-time-value.h"
 #include "src/ast/scopes.h"
 #include "src/code-factory.h"
@@ skipping 1518 matching lines @@
     __ CallStub(&stub);
   }
   PrepareForBailoutForId(expr->CreateLiteralId(), BailoutState::TOS_REGISTER);
 
   bool result_saved = false;  // Is the result saved to the stack?
   ZoneList<Expression*>* subexprs = expr->values();
   int length = subexprs->length();
 
   // Emit code to evaluate all the non-constant subexpressions and to store
   // them into the newly cloned array.
-  int array_index = 0;
-  for (; array_index < length; array_index++) {
+  for (int array_index = 0; array_index < length; array_index++) {
     Expression* subexpr = subexprs->at(array_index);
     DCHECK(!subexpr->IsSpread());
 
     // If the subexpression is a literal or a simple materialized literal it
     // is already set in the cloned array.
     if (CompileTimeValue::IsCompileTimeValue(subexpr)) continue;
 
     if (!result_saved) {
       PushOperand(rax);  // array literal
       result_saved = true;
     }
     VisitForAccumulatorValue(subexpr);
 
     __ Move(StoreDescriptor::NameRegister(), Smi::FromInt(array_index));
     __ movp(StoreDescriptor::ReceiverRegister(), Operand(rsp, 0));
     EmitLoadStoreICSlot(expr->LiteralFeedbackSlot());
     CallKeyedStoreIC();
 
     PrepareForBailoutForId(expr->GetIdForElement(array_index),
                            BailoutState::NO_REGISTERS);
   }
 
-  // In case the array literal contains spread expressions it has two parts. The
-  // first part is  the "static" array which has a literal index is  handled
-  // above. The second part is the part after the first spread expression
-  // (inclusive) and these elements gets appended to the array. Note that the
-  // number elements an iterable produces is unknown ahead of time.
-  if (array_index < length && result_saved) {
-    PopOperand(rax);
-    result_saved = false;
-  }
-  for (; array_index < length; array_index++) {
-    Expression* subexpr = subexprs->at(array_index);
-
-    PushOperand(rax);
-    DCHECK(!subexpr->IsSpread());
-    VisitForStackValue(subexpr);
-    CallRuntimeWithOperands(Runtime::kAppendElement);
-
-    PrepareForBailoutForId(expr->GetIdForElement(array_index),
-                           BailoutState::NO_REGISTERS);
-  }
-
   if (result_saved) {
     context()->PlugTOS();
   } else {
     context()->Plug(rax);
   }
 }
 
 
 void FullCodeGenerator::VisitAssignment(Assignment* expr) {
   DCHECK(expr->target()->IsValidReferenceExpressionOrThis());
@@ skipping 2023 matching lines @@
   DCHECK_EQ(
       isolate->builtins()->OnStackReplacement()->entry(),
       Assembler::target_address_at(call_target_address, unoptimized_code));
   return ON_STACK_REPLACEMENT;
 }
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_X64