This allows `run_bench.sh` to replace all previous general paired
benchmarking scripts. See `run_everything.sh` for an example of how
to use the new script.

This also fixes two critical bugs present in the old scripts:
1. The cpus_list was incorrectly set for resctrl when running
   synchronous pair timing with L2+L3 isolation (i). Each write
   to that file replaces the previous contents, and it was previously
   written once for each core. This prevented the entire 1st core
   from using any L3 cache.
2. The competing task list was indexed improperly in the asynchronous
   pair timing script. This caused the competing task to always be
   identical to the task being profiled.
These issues combine to imply that in the rejected RTSS'20 paper:
- All Level-C SMT timing data is suspect
- Level-A and -B SMT timing data with L2+L3 isolation (i) is
  wildly optimistic