[es6] support rest parameters in arrow functions (alternative)

src/compiler/ast-graph-builder.cc

Index: src/compiler/ast-graph-builder.cc
diff --git a/src/compiler/ast-graph-builder.cc b/src/compiler/ast-graph-builder.cc
index 5e5721e9db92dca7c7107a092eed6175e178027e..81846c605b23b3fe35bf4bc3bc24dfc557b9227e 100644
--- a/src/compiler/ast-graph-builder.cc
+++ b/src/compiler/ast-graph-builder.cc
@@ -2310,6 +2310,11 @@ void AstGraphBuilder::VisitCompareOperation(CompareOperation* expr) {
 }
 
 
+void AstGraphBuilder::VisitSpread(Spread* expr) {
+  UNREACHABLE();
+}
+
+
 void AstGraphBuilder::VisitThisFunction(ThisFunction* expr) {
   Node* value = GetFunctionClosure();
   ast_context()->ProduceValue(value);