NFC test if rosetta is installed before running x86 binary on AS

Rosetta 2 is not installed by default in a fresh macOS installation
on Apple Silicon, so x86 binaries cannot be run.  CI bots are often
in this state.  Update this test to check for the rosetta debugserver,
which our debugserver also hardcodes the path of, before trying to
run an x86 process on AS systems.