Flush stdout after each test.

This makes watching the valgrind tests more entertaining.
Likely makes it easier to tell what test crashed too, but let's
face it, I'm doing this to be entertained.

exec/tests/test.js

@@ -94,6 +94,7 @@ function run_tests(location, obj)
 				stdout.writeln("passed");
 				passed++;
 			}
+			stdout.flush();
 		});
 	}
 	stdout.writeln('');