Ruby - Bug #17603: `rb_bug` prints incorrect values

nobu (Nobuyoshi Nakada)
2021-02-01T04:37:05Z

Backport changed from 2.5: UNKNOWN, 2.6: UNKNOWN, 2.7: UNKNOWN, 3.0: UNKNOWN to 2.5: DONTNEED, 2.6: DONTNEED, 2.7: DONTNEED, 3.0: REQUIRED