Where is MSysConstraints?

I write this post with my fingers covered with an anti-burn cream due to the third degree burn I just got. After porting to SQL Mobile a piece of code that relied on the MSysConstraints table, my keyboard immediately turned into a flame-thrower. SQL Mobile does not have this system table (or does not expose it). What hurts me the most is that I had the chance to write this right the first time, but chose to go the easier route...