GCC 8.3.0 bug (GCC 8.5.0 and others work)

[scivision]

On multiple CentOS computers with GCC 8.3.0, this build error is observed since after h5fortran v4.4.4

h5fortran/src/write_scalar.f90:32:118:

   call hdf_create(self, dname, H5T_NATIVE_CHARACTER, dims, dims, file_space_id, dset_id, dtype_id, charlen=len(value))

                  1
Error: Type mismatch in argument 'charlen' at (1); passed INTEGER(8) to INTEGER(4)

I initially think this may be a compiler bug, let's see if we can make a workaround.
For whatever reason, various HPC default to GCC 8.3.0.

ref: gemini3d/external#4