tests: fix up recent conditionalized output changes It looks like (!) can have surprising results matching back to the original output when adjacent lines change, probably because it uses the same code matching that allows (?) to skip missing output. 24f55686a63d ended up adding unconditionalized check*{exec,link} lines, duplicating the conditionalized lines. A Windows run wanted to delete the unconditionalized lines. This now runs on both Windows and Linux.

run-tests: drop fallback for proc.terminate() for pre-py2.6