`mentionedBy.get(...) ?? []` mixes a Set<string> with an empty array
literal. scriptc compiles its own compiler, and that union has no static
representation, so the bootstrap seed build failed with SC2011 on
emitter.ts. Skip a callee without mentioners explicitly instead.
Verified with scripts/build-native-cli.mts, the build the bootstrap seed
job runs: it fails with the CI's SC2011 before this change and produces
the native CLI after it.
Malte Ubl
2d5aa4231a