Improve error reporting in selftests of testlib.

Output the file name and fix line number to be 1..n.

Change-Id: I3ba7f84b99ce3664bc3e403b230307511b15fe1f
Reviewed-by: Jędrzej Nowacki <jedrzej.nowacki@digia.com>
Reviewed-by: Frederik Gladhorn <frederik.gladhorn@digia.com>
QtCore: Fix MSVC 64bit warnings about conversion from size_t to int.

warning C4267: '=' : conversion from 'size_t' to 'int', possible loss of data

Change-Id: I9be380cbb7bed4cd95515074c7cad7e41a511dc9
Reviewed-by: Jędrzej Nowacki <jedrzej.nowacki@digia.com>