Fix #14884 fuzzing timeout (hang) in TemplateSimplifier::expandTempla… #980

Job	Run time
build (ubsan, -DANALYZE_UNDEFINED=On, true, process, true)	54m 37s
build (tsan, -DANALYZE_THREAD=On, false, thread, false, --executor=thread --error-exitcode=0)	15m 25s
build (asan, -DANALYZE_ADDRESS=On, true, process, false)	12m 30s
	1h 22m 32s

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