this commit fixes an issue observed with romio314 and the hdf5 1.10.x testsuite.
The ADIOI_Datatype_iscontig() routine in romio314/src/io_romio314_module.c
will now return for a datatype of size 0 that it is contiguous, even if the extent
of the datatype is non-zero. This avoids a segmentation fault observed in the
ADIOI_Flatten routine, and fixes this particular with the hdf5 1.10.x testsuite in
OpenMPI with romio314.
Signed-off-by: Edgar Gabriel <egabriel@central.uh.edu>
c83b47c266