Some tests hard-code source-file line numbers

During conversion of license headers for 5.15 some tests failed, as noted in tqtc-qtbase commit b98b16de25dd5463342a2165a20b5fdc1cf9c32a, because they hard-code line numbers in source files. Tests should not be sensitive to that. We neglected to record which tests those were, but it should be easy to reproduce the issue by sending a WIP, with the "padding" lines removed from tqtc/lts-5.15's headers, to Coin, for a status check build. We can then extract from its results all the relevant failures, list them in this description and then set about sorting them out one by one.