upgrade: drop support for old style optimization names Old style optimization names like `redeltaparent` were converted into `re-delta-parent` more than two years ago. The old names were kept around for sometime because of BC reasons. Refer 5608b5a6c3231c4ec771171cc3079142c7672be6. The commit states the map is there for a while and we can drop them as the underlying command is a debug command. Differential Revision: https://phab.mercurial-scm.org/D9614