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

src/ast-numbering.cc

Index: src/ast-numbering.cc
diff --git a/src/ast-numbering.cc b/src/ast-numbering.cc
index 152363e8fd0e58de555742d90b479234b6bd0f53..0150700d7b9109eb7a0e0fd9e15c08d6ef2aae99 100644
--- a/src/ast-numbering.cc
+++ b/src/ast-numbering.cc
@@ -356,6 +356,11 @@ void AstNumberingVisitor::VisitCompareOperation(CompareOperation* node) {
 }
 
 
+void AstNumberingVisitor::VisitSpread(Spread* node) {
+  UNREACHABLE();
+}
+
+
 void AstNumberingVisitor::VisitForInStatement(ForInStatement* node) {
   IncrementNodeCount();
   DisableSelfOptimization();