いえいえ大丈夫、エンバグは https://github.com/apple/swift/pull/11809 です。

今まで隠れていたバグがこれで顕在化した。 (edited)

Parser: use parser to generate a refined token stream to help syntax coloring. by nkcsgexi · Pull Request #11809 · apple/swift

This patch allows Parser to generate a refined token stream to satisfy tooling's need. For syntax coloring, token stream from lexer is insufficient because (1) we have contextual keywords like get ...