is somehow in interference with something
in the HDF4 code. So, I changed
the OPAQUE -> OPAQUE_ and that appears
to fix the problem with bison when HDF4
is enabled.
ps. when Visual Studio complained about token
'constant' it turn out that it mean token type,
not the actual token named 'constant'. Instead
the actual token that was causing the problem
was 'OPAQUE'.
This consists of a persistent attribute named
_NCProperties plus two computed attributes
_IsNetcdf4 and _SuperblockVersion.
See the 'Provenance Attributes' section
of docs/attribute_conventions.md for details.