The G1ConcurrentMark constructor uses a boolean member to indicate initialization success as it is otherwise impossible to return a value in a constructor (without exceptions we prohibit to use).

Change this construct to just do a vm_shutdown_during_initialization() at the failure conditions directly, because
 - the only caller does that already anyway, in the process giving a very generic general failure error message
 - it's kind of the only class doing error handling during initialization.
 - it adds code (member, getter, checking) for little gain