pgsql: Teach bitmap path generation about transforming OR-clauses to SA

Teach bitmap path generation about transforming OR-clauses to SAOP's

When optimizer generates bitmap paths, it considers breaking OR-clause
arguments one-by-one. But now, a group of similar OR-clauses can be
transformed into SAOP during index matching. So, bitmap paths should
keep up.

This commit teaches bitmap paths generation machinery to group similar
OR-clauses into dedicated RestrictInfos. Those RestrictInfos are considered
both to match index as a whole (as SAOP), or to match as a set of individual
OR-clause argument one-by-one (the old way).

Therefore, bitmap path generation will takes advantage of OR-clauses to SAOP's
transformation. The old way of handling them is also considered. So, there
shouldn't be planning regression.

Discussion: https://postgr.es/m/CAPpHfdu5iQOjF93vGbjidsQkhHvY2NSm29duENYH_cbhC6x%2BMg%40mail.gmail.com
Author: Alexander Korotkov, Andrey Lepikhov
Reviewed-by: Alena Rybakina, Andrei Lepikhov, Jian he, Robert Haas
Reviewed-by: Peter Geoghegan

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/ae4569161a27823793ca24825bbabce2a91a0bc9

Modified Files
--------------
src/backend/optimizer/path/indxpath.c | 430 ++++++++++++++++++++++++++++-
src/backend/optimizer/util/restrictinfo.c | 107 ++++---
src/include/optimizer/restrictinfo.h | 11 +
src/test/regress/expected/create_index.out | 125 ++++++++-
src/test/regress/expected/join.out | 56 ++--
src/test/regress/sql/create_index.sql | 38 +++
src/tools/pgindent/typedefs.list | 1 +
7 files changed, 664 insertions(+), 104 deletions(-)