Revert of [es6] implement default parameters via desugaring

src/scopes.cc

Index: src/scopes.cc
diff --git a/src/scopes.cc b/src/scopes.cc
index 98c689b4c5ce23a8a9d5ee849ffd852d265c6961..21a8805c54aad396364829e66110c72752cfd3c2 100644
--- a/src/scopes.cc
+++ b/src/scopes.cc
@@ -77,7 +77,6 @@
       internals_(4, zone),
       temps_(4, zone),
       params_(4, zone),
-      param_positions_(4, zone),
       unresolved_(16, zone),
       decls_(4, zone),
       module_descriptor_(
@@ -101,7 +100,6 @@
       internals_(4, zone),
       temps_(4, zone),
       params_(4, zone),
-      param_positions_(4, zone),
       unresolved_(16, zone),
       decls_(4, zone),
       module_descriptor_(NULL),
@@ -128,7 +126,6 @@
       internals_(0, zone),
       temps_(0, zone),
       params_(0, zone),
-      param_positions_(0, zone),
       unresolved_(0, zone),
       decls_(0, zone),
       module_descriptor_(NULL),
@@ -186,7 +183,6 @@
   module_var_ = NULL,
   rest_parameter_ = NULL;
   rest_index_ = -1;
-  has_parameter_expressions_ = false;
   scope_info_ = scope_info;
   start_position_ = RelocInfo::kNoPosition;
   end_position_ = RelocInfo::kNoPosition;
@@ -474,7 +470,7 @@
 
 
 Variable* Scope::DeclareParameter(const AstRawString* name, VariableMode mode,
-                                  bool is_rest, bool* is_duplicate, int pos) {
+                                  bool is_rest, bool* is_duplicate) {
   DCHECK(!already_resolved());
   DCHECK(is_function_scope());
   Variable* var = variables_.Declare(this, name, mode, Variable::NORMAL,
@@ -487,7 +483,6 @@
   // TODO(wingo): Avoid O(n^2) check.
   *is_duplicate = IsDeclaredParameter(name);
   params_.Add(var, zone());
-  param_positions_.Add(pos, zone());
   return var;
 }
 
@@ -555,18 +550,6 @@
 
 void Scope::AddDeclaration(Declaration* declaration) {
   decls_.Add(declaration, zone());
-}
-
-
-void Scope::UndeclareParametersForExpressions() {
-  DCHECK(is_function_scope());
-  DCHECK(!has_parameter_expressions_);
-  has_parameter_expressions_ = true;
-  for (int i = 0; i < num_parameters(); ++i) {
-    Variable* p = parameter(i);
-    const AstRawString* name = p->raw_name();
-    variables_.Remove(const_cast<AstRawString*>(name), name->hash());
-  }
 }
 
 
@@ -1436,21 +1419,16 @@
   // If it does, and if it is not copied into the context object, it must
   // receive the highest parameter index for that parameter; thus iteration
   // order is relevant!
-  //
-  // If hasParameterExpressions is true, parameters are redeclared during
-  // desugaring, and must not be allocated here.
-  if (!has_parameter_expressions_) {
-    for (int i = params_.length() - 1; i >= 0; --i) {
-      Variable* var = params_[i];
-      if (var == rest_parameter_) continue;
-
-      DCHECK(var->scope() == this);
-      if (uses_sloppy_arguments || has_forced_context_allocation()) {
-        // Force context allocation of the parameter.
-        var->ForceContextAllocation();
-      }
-      AllocateParameter(var, i);
-    }
+  for (int i = params_.length() - 1; i >= 0; --i) {
+    Variable* var = params_[i];
+    if (var == rest_parameter_) continue;
+
+    DCHECK(var->scope() == this);
+    if (uses_sloppy_arguments || has_forced_context_allocation()) {
+      // Force context allocation of the parameter.
+      var->ForceContextAllocation();
+    }
+    AllocateParameter(var, i);
   }
 }