Query: Convert null equality to Is Null in SQL before null semantics …

…are applied

One way to solve #18547

src/EFCore.Relational/Query/RelationalQueryTranslationPostprocessor.cs

@@ -36,14 +36,14 @@ public override Expression Process(Expression query)
             query = new SelectExpressionProjectionApplyingExpressionVisitor().Visit(query);
             query = new CollectionJoinApplyingExpressionVisitor().Visit(query);
             query = new TableAliasUniquifyingExpressionVisitor().Visit(query);
+            query = new NullComparisonTransformingExpressionVisitor().Visit(query);
 
             if (!UseRelationalNulls)
             {
                 query = new NullSemanticsRewritingExpressionVisitor(SqlExpressionFactory).Visit(query);
             }
 
             query = OptimizeSqlExpression(query);
-            query = new NullComparisonTransformingExpressionVisitor().Visit(query);
 
             return query;
         }