pgsql: Add BRIN infrastructure for "inclusion" opclasses

Add BRIN infrastructure for "inclusion" opclasses

This lets BRIN be used with R-Tree-like indexing strategies.

Also provided are operator classes for range types, box and inet/cidr.
The infrastructure provided here should be sufficient to create operator
classes for similar datatypes; for instance, opclasses for PostGIS
geometries should be doable, though we didn't try to implement one.

(A box/point opclass was also submitted, but we ripped it out before
commit because the handling of floating point comparisons in existing
code is inconsistent and would generate corrupt indexes.)

Author: Emre Hasegeli.  Cosmetic changes by me
Review: Andreas Karlsson

Branch
------
master

Details
-------
http://git.postgresql.org/pg/commitdiff/b0b7be61337fc64147f2ad0af5bf2c0e6b8a709f

Modified Files
--------------
doc/src/sgml/brin.sgml                   |   53 ++-
src/backend/access/brin/Makefile         |    2 +-
src/backend/access/brin/brin.c           |   90 +---
src/backend/access/brin/brin_inclusion.c |  696 ++++++++++++++++++++++++++++++
src/backend/access/brin/brin_minmax.c    |    7 +
src/backend/utils/adt/network_gist.c     |    4 +-
src/include/access/brin_internal.h       |    6 -
src/include/access/stratnum.h            |    4 +-
src/include/catalog/catversion.h         |    2 +-
src/include/catalog/pg_am.h              |    3 +-
src/include/catalog/pg_amop.h            |   37 ++
src/include/catalog/pg_amproc.h          |   23 +
src/include/catalog/pg_opclass.h         |    6 +-
src/include/catalog/pg_opfamily.h        |    3 +
src/include/catalog/pg_proc.h            |   10 +
src/test/regress/expected/brin.out       |   31 +-
src/test/regress/expected/opr_sanity.out |   25 +-
src/test/regress/sql/brin.sql            |   31 +-
18 files changed, 928 insertions(+), 105 deletions(-)