Add to_regnamespace() and to_regrole() to the documentation.
Add to_regnamespace() and to_regrole() to the documentation.

Commits cb9fa802b32b222b and 0c90f6769de6a60f added these functions,
but did not bother with documentation.

zeroae/postgres-xl,zeroae/postgres-xl,zeroae/postgres-xl,zeroae/postgres-xl,zeroae/postgres-xl