Clean up native context slots and add new ones.

src/factory.h

Index: src/factory.h
diff --git a/src/factory.h b/src/factory.h
index 72d987603950ff0ca1df00f265077ea540a3341f..96fa74da8ffd064e99201fb4ae4619cb3bfa6dec 100644
--- a/src/factory.h
+++ b/src/factory.h
@@ -551,7 +551,8 @@ class Factory final {
                           Handle<JSArray> args);
   Handle<String> EmergencyNewError(const char* message, Handle<JSArray> args);
 
-  Handle<Object> NewError(const char* constructor, Handle<String> message);
+  Handle<Object> NewError(Handle<JSFunction> constructor,
+                          Handle<String> message);
 
   Handle<Object> NewInvalidStringLengthError() {
     return NewRangeError(MessageTemplate::kInvalidStringLength);