Two tests for the magic macros `__FILE__ and `__LINE__. See also my patch set for iverilog.
The first is a simple test that they produce the right results.
The second is an advanced test. The spec states that `__FILE__ and `__LINE__ should follow `line directives. At this time the preprocessor doesn't understand how to read `line directives, only how to write them for the compiler. So, this test is expected to fail. Expect a patch in the near future ;)