Fix for a bug introduced by changeset #1629763. RequiresOptionalFields was returning true for the wrong reason for array types, and there was nothing in SaveMethodTable creating optional fields, leading to a ICE in the binder followed by a crash.
Fix for a bug introduced by changeset #1629763. RequiresOptionalFields was returning true for the wrong reason for array types, and there was nothing in SaveMethodTable creating optional fields, leading to a ICE in the binder followed by a crash.

[tfs-changeset: 1631519]

gregkalapos/corert,yizhang82/corert,botaberg/corert,gregkalapos/corert,yizhang82/corert,shrah/corert,krytarowski/corert,botaberg/corert,krytarowski/corert,shrah/corert,sandreenko/corert,tijoytom/corert,yizhang82/corert,yizhang82/corert,botaberg/corert,tijoytom/corert,botaberg/corert,tijoytom/corert,shrah/corert,shrah/corert,sandreenko/corert,tijoytom/corert,gregkalapos/corert,gregkalapos/corert,krytarowski/corert,krytarowski/corert,sandreenko/corert,sandreenko/corert