Turns out test/bench/shootout/timing.sh can already filter which tests it runs.

case $# in
0)
        run="fasta revcomp nbody binarytree fannkuch regexdna spectralnorm knucleotide mandelbrot meteor pidigits threadring chameneos"
        ;;
*)
        run=$*
esac

So test.go just needs to find that line and create sub-tests for each.

But later it'd be nice to rewrite that shell in Go, so it runs in more places.

And add a -fast flag to make it do fewer iterations (like 10 instead of 5000000), just to test coverage for the builders.

Note: now that #12668 is fixed, the coordinator should un-blacklist the "shootout" tests for linux-arm.

CL https://golang.org/cl/14738 mentions this issue.