Checked usage with git bisect:

git bisect start
git bisect bad
git checkout 3af30e728cb404a2030425ea8cb6d1845469d9b1
git bisect good
git bisect run
git bisect run grep 'normalizeCharacterLiteral(str)' lib/mathlib.cpp
git bisect reset

Last usage of duplicateDefinition in tokenize.cpp was removed in dc2a922 when simplifyEnum was removed - so it's safe to delete it.

Last usage of normalizeCharacterLiteral in mathlib.cpp was removed in f7d0bf7 - so this should be safe to remove.

The build failure was a timeout in GitHub itself.

This can be merged. All other things related to this will be resolved when the CI job for this is being added.