Stop overallocating feedback vector slots.

src/ast-numbering.cc

Index: src/ast-numbering.cc
diff --git a/src/ast-numbering.cc b/src/ast-numbering.cc
index e14b84dfe8fc26dbc27ca768e59099a7f9f432a8..8676eeb995e064ffd5bb77c7097903459286de83 100644
--- a/src/ast-numbering.cc
+++ b/src/ast-numbering.cc
@@ -11,7 +11,7 @@ namespace internal {
 
 class AstNumberingVisitor final : public AstVisitor {
  public:
-  explicit AstNumberingVisitor(Isolate* isolate, Zone* zone)
+  AstNumberingVisitor(Isolate* isolate, Zone* zone)
       : AstVisitor(),
         next_id_(BailoutId::FirstUsable().ToInt()),
         properties_(zone),
@@ -30,6 +30,10 @@ class AstNumberingVisitor final : public AstVisitor {
 
   bool Finish(FunctionLiteral* node);
 
+  void VisitVariableProxyReference(VariableProxy* node);
+  void VisitPropertyReference(Property* node);
+  void VisitReference(Expression* expr);
+
   void VisitStatements(ZoneList<Statement*>* statements) override;
   void VisitDeclarations(ZoneList<Declaration*>* declarations) override;
   void VisitArguments(ZoneList<Expression*>* arguments);
@@ -145,16 +149,21 @@ void AstNumberingVisitor::VisitRegExpLiteral(RegExpLiteral* node) {
 }
 
 
-void AstNumberingVisitor::VisitVariableProxy(VariableProxy* node) {
+void AstNumberingVisitor::VisitVariableProxyReference(VariableProxy* node) {
   IncrementNodeCount();
   if (node->var()->IsLookupSlot()) {
     DisableCrankshaft(kReferenceToAVariableWhichRequiresDynamicLookup);
   }
-  ReserveFeedbackSlots(node);
   node->set_base_id(ReserveIdRange(VariableProxy::num_ids()));
 }
 
 
+void AstNumberingVisitor::VisitVariableProxy(VariableProxy* node) {
+  VisitVariableProxyReference(node);
+  ReserveFeedbackSlots(node);
+}
+
+
 void AstNumberingVisitor::VisitThisFunction(ThisFunction* node) {
   IncrementNodeCount();
   node->set_base_id(ReserveIdRange(ThisFunction::num_ids()));
@@ -304,20 +313,35 @@ void AstNumberingVisitor::VisitTryFinallyStatement(TryFinallyStatement* node) {
 }
 
 
-void AstNumberingVisitor::VisitProperty(Property* node) {
+void AstNumberingVisitor::VisitPropertyReference(Property* node) {
   IncrementNodeCount();
-  ReserveFeedbackSlots(node);
   node->set_base_id(ReserveIdRange(Property::num_ids()));
   Visit(node->key());
   Visit(node->obj());
 }
 
 
+void AstNumberingVisitor::VisitReference(Expression* expr) {
+  DCHECK(expr->IsProperty() || expr->IsVariableProxy());
+  if (expr->IsProperty()) {
+    VisitPropertyReference(expr->AsProperty());
+  } else {
+    VisitVariableProxyReference(expr->AsVariableProxy());
+  }
+}
+
+
+void AstNumberingVisitor::VisitProperty(Property* node) {
+  VisitPropertyReference(node);
+  ReserveFeedbackSlots(node);
+}
+
+
 void AstNumberingVisitor::VisitAssignment(Assignment* node) {
   IncrementNodeCount();
   node->set_base_id(ReserveIdRange(Assignment::num_ids()));
   if (node->is_compound()) VisitBinaryOperation(node->binary_operation());
-  Visit(node->target());
+  VisitReference(node->target());
   Visit(node->value());
   ReserveFeedbackSlots(node);
 }