pgsql: Get rid of pg_class.reltoastidxid.

Get rid of pg_class.reltoastidxid.

Treat TOAST index just the same as normal one and get the OID
of TOAST index from pg_index but not pg_class.reltoastidxid.
This change allows us to handle multiple TOAST indexes, and
which is required infrastructure for upcoming
REINDEX CONCURRENTLY feature.

Patch by Michael Paquier, reviewed by Andres Freund and me.

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/2ef085d0e6960f5087c97266a7211d37ddaa9f68

Modified Files
--------------
contrib/pg_upgrade/info.c | 15 ++-
doc/src/sgml/catalogs.sgml | 9 --
doc/src/sgml/diskusage.sgml | 26 ++--
doc/src/sgml/monitoring.sgml | 4 +-
src/backend/access/heap/tuptoaster.c | 225 +++++++++++++++++++++++++++-----
src/backend/catalog/heap.c | 1 -
src/backend/catalog/index.c | 23 +---
src/backend/catalog/system_views.sql | 10 +-
src/backend/commands/cluster.c | 34 +++--
src/backend/commands/tablecmds.c | 20 ++-
src/backend/rewrite/rewriteDefine.c | 5 +-
src/backend/utils/adt/dbsize.c | 24 +++-
src/bin/pg_dump/pg_dump.c | 14 +-
src/include/access/tuptoaster.h | 9 ++
src/include/catalog/catversion.h | 2 +-
src/include/catalog/pg_class.h | 44 +++----
src/test/regress/expected/oidjoins.out | 8 --
src/test/regress/expected/rules.out | 16 +--
src/test/regress/sql/oidjoins.sql | 4 -
src/test/regress/sql/rules.sql | 2 +-
src/tools/findoidjoins/README | 1 -
21 files changed, 333 insertions(+), 163 deletions(-)