Allow Fixnum values to be quoted

lib/arel/visitors/to_sql.rb

@@ -575,6 +575,7 @@ def quoted o, a
       alias :visit_Hash                          :quoted
       alias :visit_NilClass                      :quoted
       alias :visit_String                        :quoted
+      alias :visit_Fixnum                        :quoted
       alias :visit_Symbol                        :quoted
       alias :visit_Time                          :quoted
       alias :visit_TrueClass                     :quoted

test/nodes/test_equality.rb

@@ -43,7 +43,7 @@ def quote_table_name(*args) @quote_count += 1; super; end
             attr = Table.new(:users)[:id]
             test = attr.eq(10)
             test.to_sql engine
-            engine.connection.quote_count.must_equal 2
+            engine.connection.quote_count.must_equal 3
           end
         end
       end

test/support/fake_record.rb

@@ -107,6 +107,10 @@ def columns_hash
     def schema_cache
       connection
     end
+
+    def quote *args
+      connection.quote *args
+    end
   end
 
   class Base