new test for GNL + display more info on compilation failure

[jgigault]

Proposed test for noticing about the memory management behavior of get_next_line.

This test never fails or succeed because the subject does not describe the expected behavior:

• The caller should free the lines after each call (In my opinion it is the the preferred behavior, similar to getline(3))
• The caller must not free the lines after each call, get_next_line do it itself if necessary