[es6] re-implement rest parameters via desugaring

src/preparser.h

 // 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.
 
 #ifndef V8_PREPARSER_H
 #define V8_PREPARSER_H
 
 #include "src/v8.h"
 
 #include "src/bailout-reason.h"
@@ skipping 3493 matching lines @@
   int pos = position();
   Expect(Token::SUPER, CHECK_OK);
 
   Scope* scope = scope_->DeclarationScope();
   while (scope->is_eval_scope() || scope->is_arrow_scope()) {
     scope = scope->outer_scope();
     DCHECK_NOT_NULL(scope);
     scope = scope->DeclarationScope();
   }
 
+  if (scope->is_block_scope() && scope->is_declaration_scope()) {
+    scope = scope->outer_scope();
+    DCHECK(scope->is_function_scope());
+  }
+
   FunctionKind kind = scope->function_kind();
   if (IsConciseMethod(kind) || IsAccessorFunction(kind) ||
       i::IsConstructor(kind)) {
     if (peek() == Token::PERIOD || peek() == Token::LBRACK) {
       scope->RecordSuperPropertyUsage();
       return this->SuperPropertyReference(scope_, factory(), pos);
     }
     // new super() is never allowed.
     // super() is only allowed in derived constructor
     if (!is_new && peek() == Token::LPAREN && IsSubclassConstructor(kind)) {
@@ skipping 23 matching lines @@
   int pos = position();
   Consume(Token::PERIOD);
   ExpectContextualKeyword(CStrVector("target"), CHECK_OK);
 
   Scope* scope = scope_->DeclarationScope();
   while (scope->is_eval_scope() || scope->is_arrow_scope()) {
     scope = scope->outer_scope();
     DCHECK_NOT_NULL(scope);
     scope = scope->DeclarationScope();
   }
-
+  if (scope->is_block_scope() && scope->is_declaration_scope()) {
+    // Inner function scope
+    scope = scope->outer_scope();
+    DCHECK(scope->is_function_scope());
+  }
   if (!scope->is_function_scope()) {
     ReportMessageAt(scanner()->location(),
                     MessageTemplate::kUnexpectedNewTarget);
     *ok = false;
     return this->EmptyExpression();
   }
 
   return this->NewTargetExpression(scope_, factory(), pos);
 }
 
@@ skipping 125 matching lines @@
       if (!*ok) return -1;
     } while (!parsing_state->has_rest && Check(Token::COMMA));
 
     if (parsing_state->has_rest && peek() == Token::COMMA) {
       ReportMessageAt(scanner()->peek_location(),
                       MessageTemplate::kParamAfterRest);
       *ok = false;
       return -1;
     }
   }
-
   return parameter_count;
 }
 
 
 template <class Traits>
 void ParserBase<Traits>::CheckArityRestrictions(
     int param_count, FunctionLiteral::ArityRestriction arity_restriction,
     bool has_rest, int formals_start_pos, int formals_end_pos, bool* ok) {
   switch (arity_restriction) {
     case FunctionLiteral::GETTER_ARITY:
@@ skipping 311 matching lines @@
       *ok = false;
       return;
     }
     has_seen_constructor_ = true;
     return;
   }
 }
 } }  // v8::internal
 
 #endif  // V8_PREPARSER_H