This patch no longer applies, because CATALOG_VERSION_NO in src/include/catalog/catversion.h has changed. I touched the patch and got it to apply without other problems (I haven't built yet).
Make fails:
[...]
make -C catalog schemapg.h
make[3]: se ingresa al directorio `/home/rodolfo/trabajo/postgresql/src/backend/catalog'
cd ../../../src/include/catalog && '/usr/bin/perl' ./duplicate_oids
3846
make[3]: *** [postgres.bki] Error 1
[...]
OID = 3846 is duplicated, see:
./src/include/catalog/pg_proc.h:1976:DATA(insert OID = 3846 ( pg_get_function_arg_default [...]
./src/include/catalog/pg_proc.h:4679:DATA(insert OID = 3846 ( make_date [...]