Ian Barwick <barwick(at)gmx(dot)net> writes:
> - Does src/include/postgres_ext.h count as a parser definition file?
No, it doesn't. Your experience sounds like you may have neglected to
do a full rebuild after altering NAMEDATALEN. (By default, we don't
compute object-file dependencies, so it's up to you to do "make clean"
after changing fundamental parameters.) It's unlikely that installing
Bison per se affected anything --- unless possibly you had corrupted
copies of gram.c etc.
regards, tom lane