Octave: do not dump Octave core in examples/test suite scripts

- If Octave segfaults during cleanup, it usually cannot dump its core
  and therefore just freezes, which hold up e.g Travis build jobs

Examples/octave/pointer/runme.m

@@ -1,4 +1,7 @@
-# file: runme.m
+# do not dump Octave core
+if exist("crash_dumps_octave_core", "builtin")
+  crash_dumps_octave_core(0);
+endif
 
 swigexample;