i#1703 cache simulator: use compute_tag for final_tag
i#1703 cache simulator: use compute_tag for final_tag

Switches to using compute_tag to compute final_tag in cache_t::request(),
initially for consistency, though it happens to produce a 10% speedup on
fib for unknown reasons (some interaction with compiler optimizations).

Review-URL: https://codereview.appspot.com/243670043

bl4ckic3/dynamorio,AmesianX/dynamorio,daksunt/dynamorio,bl4ckic3/dynamorio,code4bones/dynamorio,AmesianX/dynamorio,code4bones/dynamorio,code4bones/dynamorio,AmesianX/dynamorio,AmesianX/dynamorio,daksunt/dynamorio,daksunt/dynamorio,daksunt/dynamorio,code4bones/dynamorio,bl4ckic3/dynamorio,bl4ckic3/dynamorio,bl4ckic3/dynamorio,daksunt/dynamorio,AmesianX/dynamorio,code4bones/dynamorio