[es6] Re-implement rest parameters via desugaring.

src/prettyprinter.cc

Index: src/prettyprinter.cc
diff --git a/src/prettyprinter.cc b/src/prettyprinter.cc
index c5ac881be298805f18baa9bc40f498492b327e2f..a878e1a48372b592ab2d56a2c217a9cf3e157610 100644
--- a/src/prettyprinter.cc
+++ b/src/prettyprinter.cc
@@ -264,6 +264,12 @@ void CallPrinter::VisitVariableProxy(VariableProxy* node) {
 }
 
 
+void CallPrinter::VisitRestParameter(RestParameter* node) {
+  Print("...");
+  PrintLiteral(node->parameter()->name(), false);
+}
+
+
 void CallPrinter::VisitAssignment(Assignment* node) {
   Find(node->target());
   Find(node->value());
@@ -749,6 +755,12 @@ void PrettyPrinter::VisitVariableProxy(VariableProxy* node) {
 }
 
 
+void PrettyPrinter::VisitRestParameter(RestParameter* node) {
+  Print("...");
+  PrintLiteral(node->parameter()->name(), false);
+}
+
+
 void PrettyPrinter::VisitAssignment(Assignment* node) {
   Visit(node->target());
   Print(" %s ", Token::String(node->op()));
@@ -1479,6 +1491,11 @@ void AstPrinter::VisitVariableProxy(VariableProxy* node) {
 }
 
 
+void AstPrinter::VisitRestParameter(RestParameter* node) {
+  Visit(node->parameter());
+}
+
+
 void AstPrinter::VisitAssignment(Assignment* node) {
   IndentedScope indent(this, Token::Name(node->op()));
   Visit(node->target());