MDEV-3816 init-file stops getting executed if a long enough line is encountered; on a debug version, assertion `! is_set() || can_overwrite_status' fails
backport improved bootstrap error handling from 5.6

Was:
  revno: 3768.1.1
  committer: Christopher Powers <chris.powers@oracle.com>
  timestamp: Wed 2012-05-02 22:16:40 -0500
  message:
    Bug#11766342 INITIAL DB CREATION FAILS ON WINDOWS WITH AN ASSERT IN SQL_ERROR.CC
    Improved bootstrap error handling:
    - Detect and report file i/o errors
    - Report query size errors with nearest query text