re: https://github.com/Unidata/netcdf-c/issues/1977
PR https://github.com/Unidata/netcdf-c/pull/1753, changed ncgen
to allows certain type names to be used as identifiers in
selected situations.
An unwanted side effect was that existing type aliases no longer
were accepted by ncgen. Specifically, using the "long" type
caused an error.
I was able to figure out a better solution to the original
problem (https://github.com/Unidata/netcdf-c/issues/1750)
that also fixes this problem as well.
This PR fixes that problem in ncgen/ncgen.l,
and adds tests to ncdump/test_keywords.sh
