pgsql: Routine usage information schema tables

Routine usage information schema tables

Several information schema views track dependencies between
functions/procedures and objects used by them. These had not been
implemented so far because PostgreSQL doesn't track objects used in a
function body. However, formally, these also show dependencies used
in parameter default expressions, which PostgreSQL does support and
track. So for the sake of completeness, we might as well add these.
If dependency tracking for function bodies is ever implemented, these
views will automatically work correctly.

Reviewed-by: Erik Rijkers <er(at)xs4all(dot)nl>
Discussion: https://www.postgresql.org/message-id/flat/ac80fc74-e387-8950-9a31-2560778fc1e3%40enterprisedb.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/f40c6969d0eddfc6de786006bd1048961a65a0eb

Modified Files
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doc/src/sgml/information_schema.sgml | 443 ++++++++++++++++++++++++
src/backend/catalog/information_schema.sql | 100 +++++-
src/backend/catalog/sql_features.txt | 2 +-
src/include/catalog/catversion.h | 2 +-
src/test/regress/expected/create_function_3.out | 38 ++
src/test/regress/sql/create_function_3.sql | 24 ++
6 files changed, 603 insertions(+), 6 deletions(-)