review of: collation for (expr)

Compiling on Ubuntu 10.04 LTS AMD64 on a GoGrid virtual machine from
2012-01-12 checkout.

Bison upgraded to v2.5, and downgraded to v2.4.1

Make process for both versions resulted in the following errors:

make[3]: Leaving directory `/usr/local/src/pgbuild/src/backend/catalog'
make -C parser gram.h
make[3]: Entering directory `/usr/local/src/pgbuild/src/backend/parser'
/usr/local/bin/bison -d -o gram.c gram.y
gram.y: conflicts: 370 reduce/reduce
gram.y: expected 0 reduce/reduce conflicts
gram.y:10482.27-10494.33: warning: rule useless in parser due to conflicts:
func_expr: COLLATION FOR '(' a_expr ')'
make[3]: *** [gram.c] Error 1
make[3]: Leaving directory `/usr/local/src/pgbuild/src/backend/parser'
make[2]: *** [parser/gram.h] Error 2
make[2]: Leaving directory `/usr/local/src/pgbuild/src/backend'
make[1]: *** [all-backend-recurse] Error 2
make[1]: Leaving directory `/usr/local/src/pgbuild/src'
make: *** [all-src-recurse] Error 2