Shouldn't have committed this! Revert "avoid calling to_sql twice"

This reverts commit 1c030a3.

activerecord/lib/active_record/relation/query_methods.rb

@@ -135,14 +135,11 @@ def build_arel
         next if where.blank?
 
         case where
-        when Arel::Predicates::In
-          # FIXME: this needs to go away
-          # when an IN is part of a larger query, the SQL seems to be different
-          arel = arel.where(Arel::SqlLiteral.new("(#{where.to_sql})"))
-        when String
-          arel = arel.where(Arel::SqlLiteral.new("(#{where})"))
+        when Arel::SqlLiteral
+          arel = arel.where(where)
         else
-          arel = arel.where where
+          sql = where.is_a?(String) ? where : where.to_sql
+          arel = arel.where(Arel::SqlLiteral.new("(#{sql})"))
         end
       end