Merge branch '6.0' into datetimeoffset-accessor-on-x86-issue

# Conflicts:
#	ChangeLog/6.0.10_dev.txt

Author: alex-kulakov

ChangeLog/6.0.10_dev.txt

@@ -1 +1,2 @@
-[main] Fixed NotSupportedException appeared on x86 architecture when DateTimeOffset is used in entites
+[main] Fixed certain cases of NRE happened on Domain build due to views in extracted schema
+[main] Fixed NotSupportedException appeared on x86 architecture when DateTimeOffset is used in entites

Orm/Xtensive.Orm/Orm/Upgrade/Internals/CatalogCloner.cs

@@ -157,7 +157,9 @@ private void CloneViews(Schema newSchema, Schema sourceSchema)
         var newView = newSchema.CreateView(sourceView.Name);
         CopyDbName(newView, sourceView);
         newView.CheckOptions = sourceView.CheckOptions;
-        newView.Definition = (SqlNative) sourceView.Definition.Clone();
+        if (sourceView.Definition != null) {
+          newView.Definition = (SqlNative) sourceView.Definition.Clone();
+        }
         CloneViewColumns(newView, sourceView);
         CloneIndexes(newView, sourceView);
       }