Add catches_strings test to test throws char * typemap

Examples/test-suite/octave/catches_strings_runme.m

@@ -0,0 +1,19 @@
+# do not dump Octave core
+if exist("crash_dumps_octave_core", "builtin")
+  crash_dumps_octave_core(0);
+endif
+
+catches_strings
+
+exception_thrown = false;
+try
+  StringsThrower.charstring();
+catch e
+  if (isempty(strfind(e.message, "charstring message")))
+    error("incorrect exception message: %s", e.message)
+  endif
+  exception_thrown = true;
+end_try_catch
+if (!exception_thrown)
+  error("Should have thrown an exception");
+endif