pgsql: Skip not SOAP-supported indexes while transforming an OR clause

Skip not SOAP-supported indexes while transforming an OR clause into SAOP

There is no point in transforming OR-clauses into SAOP's if the target index
doesn't support SAOP scans anyway.  This commit adds corresponding checks
to match_orclause_to_indexcol() and group_similar_or_args().  The first check
fixes the actual bug, while the second just saves some cycles.

Reported-by: Alexander Lakhin
Discussion: https://postgr.es/m/8174de69-9e1a-0827-0e81-ef97f56a5939%40gmail.com
Author: Alena Rybakina
Reviewed-by: Ranier Vilela, Alexander Korotkov, Andrei Lepikhov

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/5bba0546eecb32f4ff9388815727304823940ef6

Modified Files
--------------
src/backend/optimizer/path/indxpath.c      | 11 +++++++++--
src/test/regress/expected/create_index.out | 18 ++++++++++++++++++
src/test/regress/sql/create_index.sql      |  6 ++++++
3 files changed, 33 insertions(+), 2 deletions(-)