[cleanup] Remove cruft from old rest parameter implementation

Review URL: https://codereview.chromium.org/1485823003

Cr-Commit-Position: refs/heads/master@{#32535}

src/ast/ast-value-factory.h

@@ -263,7 +263,6 @@ class AstValue : public ZoneObject {
   F(next, "next")                               \
   F(proto, "__proto__")                         \
   F(prototype, "prototype")                     \
-  F(rest_parameter, ".rest_parameter")          \
   F(this, "this")                               \
   F(this_function, ".this_function")            \
   F(undefined, "undefined")                     \

src/ast/scopes.cc

@@ -205,7 +205,6 @@ void Scope::SetDefaults(ScopeType scope_type, Scope* outer_scope,
   arity_ = 0;
   has_simple_parameters_ = true;
   rest_parameter_ = NULL;
-  rest_index_ = -1;
   scope_info_ = scope_info;
   start_position_ = RelocInfo::kNoPosition;
   end_position_ = RelocInfo::kNoPosition;
@@ -522,7 +521,6 @@ Variable* Scope::DeclareParameter(
   if (is_rest) {
     DCHECK_NULL(rest_parameter_);
     rest_parameter_ = var;
-    rest_index_ = num_parameters();
   }
   params_.Add(var, zone());
   return var;

src/ast/scopes.h

@@ -420,17 +420,6 @@ class Scope: public ZoneObject {
 
   int num_parameters() const { return params_.length(); }
 
-  // A function can have at most one rest parameter. Returns Variable* or NULL.
-  Variable* rest_parameter(int* index) const {
-    *index = rest_index_;
-    if (rest_index_ < 0) return NULL;
-    return rest_parameter_;
-  }
-
-  bool has_rest_parameter() const {
-    return rest_index_ >= 0;
-  }
-
   bool has_simple_parameters() const {
     return has_simple_parameters_;
   }
@@ -690,7 +679,6 @@ class Scope: public ZoneObject {
   int arity_;
   bool has_simple_parameters_;
   Variable* rest_parameter_;
-  int rest_index_;
 
   // Serialized scope info support.
   Handle<ScopeInfo> scope_info_;