Fix nvfortran HDF5 complex type compatibility

[krystophny]

Problem

Building libneo with nvfortran fails when compiling src/hdf5_tools/hdf5_tools.F90 due to complex type handling:

NVFORTRAN-S-0155-Could not resolve generic procedure h5dread_f (hdf5_tools.F90: 1279)
NVFORTRAN-S-0155-Could not resolve generic procedure h5dread_f (hdf5_tools.F90: 1280)

Root Cause

Lines 1279-1280 use val%re and val%im syntax to access real/imaginary components of complex arrays, which is a GCC extension. The code has a preprocessor workaround for Intel and old GCC, but nvfortran (NVHPC) is not included:

#if defined(__INTEL_COMPILER) || (defined(__GNUC__) && (__GNUC__ < 9))
    ! Uses temp arrays (works)
#else
    call h5dread_f(dset_id, dt_re_id, val%re, dims, h5error)  ! Fails with nvfortran
    call h5dread_f(dset_id, dt_im_id, val%im, dims, h5error)
#endif

Solution

Add __NVCOMPILER to the preprocessor check at lines 1278, 1298, and similar locations:

#if defined(__INTEL_COMPILER) || defined(__NVCOMPILER) || (defined(__GNUC__) && (__GNUC__ < 9))

This affects h5_get_complex_1, h5_get_complex_2, and h5_get_complex_3 subroutines.

Impact

• Blocks full library build with nvfortran
• GPU benchmarks work (standalone build), but full test suite cannot run