hdf5_ep

Merge pull request #1511 in HDFFV/hdf5 from ~BYRN/hdf5_adb:hdf5_1_8 to hdf5_1_8

* commit '8d496b728ac613efd277ff7a7fb2c7e76e5d54b8':
  Correct regular test handling
  Correct VFD test logic