[runtime] Allocate space for computed property names

src/ast/ast.cc

Index: src/ast/ast.cc
diff --git a/src/ast/ast.cc b/src/ast/ast.cc
index c63f90ecf11f398ebfdecf5c6fd25356dd934f83..173d4059e94ef6f56051ee390ef4ec76714febad 100644
--- a/src/ast/ast.cc
+++ b/src/ast/ast.cc
@@ -582,9 +582,10 @@ void ObjectLiteral::InitDepthAndFlags() {
 void ObjectLiteral::BuildConstantProperties(Isolate* isolate) {
   if (!constant_properties_.is_null()) return;
 
-  // Allocate a fixed array to hold all the constant properties.
-  Handle<FixedArray> constant_properties =
-      isolate->factory()->NewFixedArray(boilerplate_properties_ * 2, TENURED);
+  // Allocate a fixed array to hold all the constant properties and the number
+  // of total properties.
+  Handle<FixedArray> constant_properties = isolate->factory()->NewFixedArray(
+      boilerplate_properties_ * 2 + 1, TENURED);
 
   int position = 0;
   for (int i = 0; i < properties()->length(); i++) {
@@ -622,6 +623,10 @@ void ObjectLiteral::BuildConstantProperties(Isolate* isolate) {
     constant_properties->set(position++, *value);
   }
 
+  Handle<Object> total_properties = isolate->factory()->NewNumberFromInt(
+      properties()->length() - (has_seen_proto() ? 1 : 0));
+  constant_properties->set(position, *total_properties);
+
   constant_properties_ = constant_properties;
 }