Add some error checking, and stop assuming what the input
will necessarily contain. Allow defined nodes to use any
intN_t or unintN_t (as well as plain old int) data types
in fields (along with the others that are permitted).
Note: this script is a part of the build procedure for /bin/sh,
the modified version generates the exact same output files
(for the unaltered input specifications) as the previous one
did, hence no visible change is expected (or even possible).
While there is a tiny chance that some host shell will fail
to be able to run this script while building, the script still
uses nothing even slightly exotic, and is much more conservative
than other scripts used during the build process, so there should
be no issues there either.
UnifiedSplitRaw