We don't need additional type casting for locking updates

Part of the larger refactoring to remove type casting from Arel. We can
inform it that we already have the right type by wrapping the value in
an `Arel::Nodes::Quoted`. This commit can be reverted when we have
removed type casting from Arel in Rail 5.1

activerecord/lib/active_record/locking/optimistic.rb

@@ -80,10 +80,18 @@ def _update_record(attribute_names = self.attribute_names) #:nodoc:
           begin
             relation = self.class.unscoped
 
-            stmt = relation.where(
-              relation.table[self.class.primary_key].eq(id).and(
-                relation.table[lock_col].eq(self.class.quote_value(previous_lock_value, column_for_attribute(lock_col)))
+            # FIXME: Remove the Arel::Nodes::Quoted when we remove type casting
+            # from Arel (Rails 5.1)
+            quoted_lock_value = Arel::Nodes::Quoted.new(
+              self.class.quote_value(
+                previous_lock_value,
+                column_for_attribute(lock_col),
               )
+            )
+            quoted_id = Arel::Nodes::Quoted.new(id)
+            stmt = relation.where(
+              relation.table[self.class.primary_key].eq(quoted_id).and(
+                relation.table[lock_col].eq(quoted_lock_value))
             ).arel.compile_update(
               arel_attributes_with_values_for_update(attribute_names),
               self.class.primary_key