client/mysql.cc:
  Don't remove MariaDB executable comments.
mysql-test/r/comments.result:
  Test MariaDB executable comments.
mysql-test/r/mysql.result:
  Test MariaDB executable comments.
mysql-test/t/comments.test:
  Test MariaDB executable comments.
mysql-test/t/mysql.test:
  Test MariaDB executable comments.
sql/sql_cache.cc:
  Don't delete MariaDB executable comments.
sql/sql_lex.cc:
  Handle MariaDB executable comments