gcc_release (announce_snapshot): Use ${RELEASE} instead of ${BRANCH}-${DATE} to refer to the snapshot directory.
* gcc_release (announce_snapshot): Use ${RELEASE} instead
of ${BRANCH}-${DATE} to refer to the snapshot directory.
Put README file into the snapshot directory.
(RELEASE): Define as ${BRANCH}-${DATE} for snapshots.
(FTP_PATH): Use ${RELEASE} in case of snapshots.
(TAG): Ditto.
(OLD_TARS): Adjust to new directory scheme for snapshots.