pgsql: Fix dependency, when changing a function's argument/return type.

Fix dependency, when changing a function's argument/return type.

When a new base type is created using the old-style procedure of first
creating the input/output functions with "opaque" in place of the base
type, the "opaque" argument/return type is changed to the final base type,
on CREATE TYPE. However, we did not create a pg_depend record when doing
that, so the functions were left not depending on the type.

Fixes bug #14706, reported by Karen Huddleston.

Discussion: https://www.postgresql.org/message-id/20170614232259.1424.82774@wrigleys.postgresql.org

Branch
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REL9_2_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/ac93a78b0e51b69bfccd7b548da4f2d4ebf7cf93

Modified Files
--------------
src/backend/commands/functioncmds.c | 32 +++++++++++++++++++++++++++++++
src/test/regress/expected/create_type.out | 31 ++++++++++++++++++++++++++++++
src/test/regress/sql/create_type.sql | 17 ++++++++++++++++
3 files changed, 80 insertions(+)