Use process group to kill children instead of parent PIDs

Using the process group (now that we've got one that's exclusive
to the testrunner) allows us to also clean up children that have
been detached from their original parent (and now have PID 1 as
their parent).

tests/testrunner.sh

@@ -228,18 +228,23 @@ function testrunner::signal_children()
     local child_pids=()
 
     IFS=
-    res=$(ps -o ppid,pid)
+    res=$(ps -o pgid,ppid,pid)
     unset IFS
     {
         read -r # Skip header
-        while IFS=' ' read -r ppid cpid; do
-            test $ppid -eq $pid && child_pids+=($cpid)
+        while IFS=' ' read -r pgid ppid cpid; do
+            # Child processes
+            #test $ppid -eq $pid && child_pids+=($cpid)
+            # Process group children
+            test $pgid -eq $pid && test $cpid -ne $pid && child_pids+=($cpid)
         done
     }<<<"$res"
 
-    local p
+    IFS=$'\n' child_pids=($(sort --reverse <<<"${child_pids[*]}"))
+
     for p in "${child_pids[@]}"; do
-        testrunner::signal_children $signal $p
+        #testrunner::signal_children $signal $p
+        #echo "Signaling $p ($(ps -o pid=,command= $p)) $signal"
         kill -$signal $p >/dev/null 2>&1
     done
 }
@@ -299,7 +304,8 @@ for testsuite in "${testsuites[@]}"; do
         printf "tests_total+=${tests_total}; tests_failed+=${tests_failed}" >&3
 
         # Clean up if test didn't do it
-        testrunner::signal_children TERM
+        testrunner::signal_children TERM $$
+        testrunner::signal_children KILL $$
     )
     exec 4>&-
     if [[ $interrupted -eq 1 ]]; then