fix #957: remove unused dtype trait for size_t
fix #957: remove unused dtype trait for size_t

shehzan10/arrayfire,umar456/arrayfire,umar456/arrayfire,marbre/arrayfire,arrayfire/arrayfire,victorv/arrayfire,marbre/arrayfire,pombredanne/arrayfire,arrayfire/arrayfire,bkloppenborg/arrayfire,9prady9/arrayfire,jramapuram/arrayfire,bkloppenborg/arrayfire,victorv/arrayfire,ghisvail/arrayfire,mrgloom/arrayfire,shehzan10/arrayfire,merlin-ext/arrayfire,munnybearz/arrayfire,arrayfire/arrayfire,umar456/arrayfire,mrgloom/arrayfire,victorv/arrayfire,marbre/arrayfire,jramapuram/arrayfire,mrgloom/arrayfire,hshindo/arrayfire,ghisvail/arrayfire,jramapuram/arrayfire,9prady9/arrayfire,pombredanne/arrayfire,hshindo/arrayfire,pentschev/arrayfire,hshindo/arrayfire,merlin-ext/arrayfire,bkloppenborg/arrayfire,victorv/arrayfire,pentschev/arrayfire,merlin-ext/arrayfire,marbre/arrayfire,munnybearz/arrayfire,ghisvail/arrayfire,mrgloom/arrayfire,shehzan10/arrayfire,shehzan10/arrayfire,umar456/arrayfire,hshindo/arrayfire,merlin-ext/arrayfire,pentschev/arrayfire,9prady9/arrayfire,ghisvail/arrayfire,arrayfire/arrayfire,munnybearz/arrayfire,pombredanne/arrayfire,bkloppenborg/arrayfire,9prady9/arrayfire,pentschev/arrayfire,pombredanne/arrayfire,jramapuram/arrayfire