You can save the source as partition.c and use:
gcc -O2 -Wall -Wmissing-prototypes -Wpointer-arith -Wdeclaration-after-statement -Wendif-labels -Wmissing-format-attribute -Wformat-security -fno-strict-aliasing -fwrapv -fpic -DREFINT_VERBOSE -I. -I. -I"/usr/pgsql-9.2/include/server/" -D_GNU_SOURCE -c -o partition.o partition.c
gcc -O2 -Wall -Wmissing-prototypes -Wpointer-arith -Wdeclaration-after-statement -Wendif-labels -Wmissing-format-attribute -Wformat-security -fno-strict-aliasing -fwrapv -fpic -Wl,--as-needed -Wl,-rpath,'/usr/local/pgsql/lib',--enable-new-dtags -L/usr/pgsql-9.2/lib -lpgport -shared -o /usr/pgsql-9.2/lib/partition.so
To Compile you must have postgresql-devel packages.
I've added everything to github:
https://github.com/charlesrg/pgsql_partition/blob/master/partition.c
For more info check
http://www.charlesrg.com/linux/71-postgresql-partitioning-the-database-the-fastest-way
Now the compilation is OK.
I'll test and feed back more information if any.
best regards
Ali