Work-item functions return 0 if dim out of range.
Work-item functions return 0 if dim out of range.

mpflanzer/Oclgrind,bitfusionio/Oclgrind,mpflanzer/Oclgrind,bitfusionio/Oclgrind,mpflanzer/Oclgrind,surround-io/oclgrind,bitfusionio/Oclgrind,mpflanzer/Oclgrind,bitfusionio/Oclgrind,surround-io/oclgrind,surround-io/oclgrind,surround-io/oclgrind