Rollback #14510 because it causes remote test execution to fail

tools/test/test-setup.sh

@@ -331,9 +331,18 @@ fi
 childPid=$!
 
 # Cleanup helper
-# Assume that we don't have drastically reduced abilities to communicate signals
-# to our parent process. kill()ability means existence.
-( while kill -0 $PPID &> /dev/null; do  # magic 0 sigspec tests deliverability only
+# It would be nice to use `kill -0 $PPID` here, but when whatever called this
+# is running as a different user (as happens in remote execution) that will 
+# return an error, causing us to prematurely reap a running test.
+( if ! (ps -p $$ &> /dev/null || [ "`pgrep -a -g $$ 2> /dev/null`" != "" ] ); then
+   # `ps` is known to be unrunnable in the darwin sandbox-exec environment due
+   # to being a set-uid root program. pgrep exists in most environments, but not
+   # universally. In the event that we find ourselves running in an environment
+   # where *neither* exists, we have no reliable way to check if our parent is
+   # still alive - so simply disable this cleanup routine entirely.
+   exit 0
+ fi
+ while ps -p $$ &> /dev/null || [ "`pgrep -a -g $$ 2> /dev/null`" != "" ]; do
     sleep 10
  done
  # Parent process not found - we've been abandoned! Clean up test processes.