Add missing header include

This was preventing the extension from building on Oracle Linux 8

Stamp 18beta1.

Stamp 17.5.

Stamp 16.9.

Stamp 15.13.

Stamp 14.18.

Stamp 13.21.

Pass proper old rlocator to smgr when creating relations and indexes (#…

…156)

Stamp 17.4.

Stamp 16.8.