ioshark: A Repeatable Application Workload Based Storage Benchmark.

ioshark:  A Repeatable Application Workload Based Storage Benchmark.

ioshark is a repeatable application storage workload benchmark. ioshark
takes as input strace files, compiles them into bytecodes that you can
then feed into the benchmark. This allows us to collect straces for a
chosen application workload (by stracing zygote/zygote64), and use
these to do A-B comparisons of storage features (anything including the
filesystem and below, including new hardware).

Test: Extra tests for ioshark aren't needed, ioshark reports detailed
stats at the end of the run, which tells us whether the ioshark run
was successful or not. In addition, we can strace ioshark_bench as it
runs to make sure it is launching IOs as we would expect it to.

Change-Id: I70674ff8daac229b9f8e5d37780f15c7a31a7ca0
Signed-off-by: Mohan Srinivasan <srmohan@google.com>