pgsql: Refactor reloption handling for index AMs in-core

Refactor reloption handling for index AMs in-core

This reworks the reloption parsing and build of a couple of index AMs by
creating new structures for each index AM's options. This split was
already done for BRIN, GIN and GiST (which actually has a fillfactor
parameter), but not for hash, B-tree and SPGiST which relied on
StdRdOptions due to an overlap with the default option set.

This saves a couple of bytes for rd_options in each relcache entry with
indexes making use of relation options, and brings more consistency
between all index AMs. While on it, add a couple of AssertMacro() calls
to make sure that utility macros to grab values of reloptions are used
with the expected index AM.

Author: Nikolay Shaplov
Reviewed-by: Amit Langote, Michael Paquier, Álvaro Herrera, Dent John
Discussion: https://postgr.es/m/4127670.gFlpRb6XCm@x200m

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/4cb658af70027c3544fb843d77b2e84028762747

Modified Files
--------------
src/backend/access/common/reloptions.c | 4 +---
src/backend/access/hash/hashpage.c | 2 +-
src/backend/access/hash/hashutil.c | 9 ++++++++-
src/backend/access/nbtree/nbtree.c | 4 ++--
src/backend/access/nbtree/nbtsort.c | 4 ++--
src/backend/access/nbtree/nbtsplitloc.c | 2 +-
src/backend/access/nbtree/nbtutils.c | 13 ++++++++++++-
src/backend/access/spgist/spgutils.c | 13 ++++++++++---
src/include/access/brin.h | 8 ++++++--
src/include/access/gin_private.h | 9 +++++++--
src/include/access/hash.h | 16 ++++++++++++++++
src/include/access/nbtree.h | 18 ++++++++++++++++++
src/include/access/spgist.h | 4 ----
src/include/access/spgist_private.h | 22 ++++++++++++++++++++++
src/include/utils/rel.h | 3 +--
src/tools/pgindent/typedefs.list | 3 +++
16 files changed, 110 insertions(+), 24 deletions(-)