Revert "VM: [Kernel] Avoid emitting :expr_temp and capturing :iterator"

runtime/vm/kernel_to_il.cc

Index: runtime/vm/kernel_to_il.cc
diff --git a/runtime/vm/kernel_to_il.cc b/runtime/vm/kernel_to_il.cc
index 1b23d09f13fdfe00fcb9bec92bc76524668fd3e9..0fc5196ca90ca2f30cd5e5e512aedfbd20607d1c 100644
--- a/runtime/vm/kernel_to_il.cc
+++ b/runtime/vm/kernel_to_il.cc
@@ -31,32 +31,6 @@ namespace kernel {
 #define I Isolate::Current()
 
 
-class NeedsExprTempVisitor : public RecursiveVisitor {
- public:
-  NeedsExprTempVisitor() : needs_expr_temp_(false) {}
-
-  virtual void VisitConditionalExpression(ConditionalExpression* node) {
-    needs_expr_temp_ = true;
-  }
-
-  virtual void VisitLogicalExpression(LogicalExpression* node) {
-    needs_expr_temp_ = true;
-  }
-
-  bool needs_expr_temp() const { return needs_expr_temp_; }
-
- private:
-  bool needs_expr_temp_;
-};
-
-
-static bool NeedsExprTemp(TreeNode* node) {
-  NeedsExprTempVisitor visitor;
-  node->AcceptVisitor(&visitor);
-  return visitor.needs_expr_temp();
-}
-
-
 static void DiscoverEnclosingElements(Zone* zone,
                                       const Function& function,
                                       Function* outermost_function,
@@ -125,9 +99,6 @@ void ScopeBuilder::AddParameter(VariableDeclaration* declaration,
   if (declaration->IsFinal()) {
     variable->set_is_final();
   }
-  if (variable->name().raw() == Symbols::IteratorParameter().raw()) {
-    variable->set_is_forced_stack();
-  }
   scope_->InsertParameterAt(pos, variable);
   result_->locals.Insert(declaration, variable);
 
@@ -329,11 +300,7 @@ ScopeBuildingResult* ScopeBuilder::BuildScopes() {
   LocalVariable* context_var = parsed_function->current_context_var();
   context_var->set_is_forced_stack();
   scope_->AddVariable(context_var);
-  bool has_expr_temp = false;
-  if (node_ != NULL && NeedsExprTemp(node_)) {
-    scope_->AddVariable(parsed_function->EnsureExpressionTemp());
-    has_expr_temp = true;
-  }
+  scope_->AddVariable(parsed_function->EnsureExpressionTemp());
 
   parsed_function->SetNodeSequence(
       new SequenceNode(TokenPosition::kNoSource, scope_));
@@ -381,10 +348,6 @@ ScopeBuildingResult* ScopeBuilder::BuildScopes() {
             Field* field = klass->fields()[i];
             if (!field->IsStatic() && (field->initializer() != NULL)) {
               EnterScope(field, field->position());
-              if (!has_expr_temp && NeedsExprTemp(field->initializer())) {
-                scope_->AddVariable(parsed_function->EnsureExpressionTemp());
-                has_expr_temp = true;
-              }
               field->initializer()->AcceptExpressionVisitor(this);
               ExitScope(field->end_position());
             }