Clean up native context slots and add new ones.

src/isolate.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <stdlib.h>
 
 #include <fstream>  // NOLINT(readability/streams)
 #include <sstream>
 
 #include "src/v8.h"
@@ skipping 314 matching lines @@
       return false;
     }
   }
   return true;
 }
 
 
 Handle<Object> Isolate::CaptureSimpleStackTrace(Handle<JSObject> error_object,
                                                 Handle<Object> caller) {
   // Get stack trace limit.
-  Handle<Object> error = Object::GetProperty(
-      this, js_builtins_object(), "$Error").ToHandleChecked();
-  if (!error->IsJSObject()) return factory()->undefined_value();
-
+  Handle<JSObject> error = error_function();
   Handle<String> stackTraceLimit =
       factory()->InternalizeUtf8String("stackTraceLimit");
   DCHECK(!stackTraceLimit.is_null());
-  Handle<Object> stack_trace_limit = JSReceiver::GetDataProperty(
-      Handle<JSObject>::cast(error), stackTraceLimit);
+  Handle<Object> stack_trace_limit =
+      JSReceiver::GetDataProperty(error, stackTraceLimit);
   if (!stack_trace_limit->IsNumber()) return factory()->undefined_value();
   int limit = FastD2IChecked(stack_trace_limit->Number());
   limit = Max(limit, 0);  // Ensure that limit is not negative.
 
   int initial_size = Min(limit, 10);
   Handle<FixedArray> elements =
       factory()->NewFixedArrayWithHoles(initial_size * 4 + 1);
 
   // If the caller parameter is a function we skip frames until we're
   // under it before starting to collect.
@@ skipping 983 matching lines @@
     }
   }
   return false;
 }
 
 
 // Traverse prototype chain to find out whether the object is derived from
 // the Error object.
 bool Isolate::IsErrorObject(Handle<Object> obj) {
   if (!obj->IsJSObject()) return false;
-
-  Handle<String> error_key =
-      factory()->InternalizeOneByteString(STATIC_CHAR_VECTOR("$Error"));
-  Handle<Object> error_constructor = Object::GetProperty(
-      js_builtins_object(), error_key).ToHandleChecked();
-
+  Handle<Object> error_constructor = error_function();
   DisallowHeapAllocation no_gc;
   for (PrototypeIterator iter(this, *obj, PrototypeIterator::START_AT_RECEIVER);
        !iter.IsAtEnd(); iter.Advance()) {
     if (iter.GetCurrent()->IsJSProxy()) return false;
     if (JSObject::cast(iter.GetCurrent())->map()->GetConstructor() ==
         *error_constructor) {
       return true;
     }
   }
   return false;
@@ skipping 1462 matching lines @@
   // Then check whether this scope intercepts.
   if ((flag & intercept_mask_)) {
     intercepted_flags_ |= flag;
     return true;
   }
   return false;
 }
 
 }  // namespace internal
 }  // namespace v8