Tools: scripts: add dumpstack

Given a pid this script attempts to dump a stack trace of that process
to stderr

Tools/scripts/dumpstack

@@ -0,0 +1,15 @@
+#!/bin/sh
+
+# we want everything on stderr, so the program is not disturbed
+exec 1>&2
+
+PID=$1
+TMPFILE=/tmp/gdb.$$
+cat << EOF  > $TMPFILE
+set height 0
+bt full
+thread apply all bt full
+quit
+EOF
+gdb -batch -x $TMPFILE --pid $PID < /dev/null 2>&1
+/bin/rm -f $TMPFILE