some `Check::FileInfo`/`CTU::FileInfo` usage cleanups #658

Job	Run time
build (ubsan, -DANALYZE_UNDEFINED=On, true, process, true)	54m 57s
build (tsan, -DANALYZE_THREAD=On, false, thread, false, --executor=thread --error-exitcode=0)	18m 49s
build (asan, -DANALYZE_ADDRESS=On, true, process, false)	15m 54s
	1h 29m 40s

Provide feedback