Clean up dead code after spread desugaring

src/ast/ast-literal-reindexer.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 "src/ast/ast-literal-reindexer.h"
 
 #include "src/ast/ast.h"
 #include "src/ast/scopes.h"
 
 namespace v8 {
@@ skipping 170 matching lines @@
 }
 
 
 void AstLiteralReindexer::VisitCompareOperation(CompareOperation* node) {
   Visit(node->left());
   Visit(node->right());
 }
 
 
 void AstLiteralReindexer::VisitSpread(Spread* node) {
+  // This is reachable because ParserBase::ParseArrowFunctionLiteral calls
+  // ReindexLiterals before calling RewriteDestructuringAssignments.
   Visit(node->expression());
 }
 
 
 void AstLiteralReindexer::VisitEmptyParentheses(EmptyParentheses* node) {}
 
 
 void AstLiteralReindexer::VisitForInStatement(ForInStatement* node) {
   Visit(node->each());
   Visit(node->enumerable());
@@ skipping 122 matching lines @@
 void AstLiteralReindexer::VisitFunctionLiteral(FunctionLiteral* node) {
   // We don't recurse into the declarations or body of the function literal:
 }
 
 
 void AstLiteralReindexer::Reindex(Expression* pattern) {
   pattern->Accept(this);
 }
 }  // namespace internal
 }  // namespace v8