Use planner hints on PostgreSQL

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Support PostgreSQL 13.

- Follow change of some planner functions.

- Follow a change of the semantics of List.

- Take in changes in copied core code.

- Adjust regression tests.
Amost all of the differences are come from aliasing policy, and some
come from a new GUC parameter.

Version 1.3.6.

Fixed some bugs.

Add description of *ScanRegExp hints in the document.

English version of hint list is missing regexp versions of scan
hints. Add them.

Mask non-significant parts of regression output

To stabilize test, mask more of non-significant parts of EXPLAIN output.

Fix segfault when use Set, Rows and Parallel hints together

Fix some spelling errors in comments

Mark hint table as a configuration table.

The table hint_plan.hints is a configuration table of
pg_hint_plan. Mark it as such, as well as its sequence table.

Back patch to pg_hint_plan96.

Preparation for branch PG12

Change version to 12-1.3.5. Adjust SPEC file.

Support PG12.

As the prepparation for making PG12 branch, change PG version to 12
and adjust for the latest PG12.

Change copyright year to 2020.

Restore current hint state when returned from non-hinted query planning.

If no hint is given for the current level query, pg_hint_plan_planner
calls the next level of planner after erasing the
current_hint_state. But it forgot to restore the state before the
planning of the rest part of the current-level query. It is
(a-kind-of) broken by the commit d422966 but overlooked as an
inevitable side-effect of the fix. Get back the behavior by restoring
current_hint_state after returned from the lower level planner with
unhinted query.

Issue: https://github.com/ossc-db/pg_hint_plan/issues/30
Reported-by: higuchi-daisuke

Use proper type for non-integer GUC options.

pg_hint_plan internally preserved numeric options into integer
variable regardless of their types, which leads to unintentional
change of the values. Handle double values in the proper way.

Fix Rows hint parsing

This is a long standing bug that Rows hint with no parameter causees a
crash. Fixed the Rows hint parser.

Give correct query location to generate_normalized_query.

There was a thinko about query_loc of generate_normalized_query which
causes a crash. For example a query is following a sequence of
semicolons (by \; in psql input) longer than the length after the last
placeholder to the end of the query, the function causes assertion
failure. Anyway prepared statements lose that value so we just pass 0
as the query_loc for consistent behavior.

Fix behavior of nested planning

Issue: https://github.com/ossc-db/pg_hint_plan/issues/39

When planning is nested by function call, the hints in the function
should affect the corresponding query. Maybe 9599067 introduced
that. Fix the nested planning behavior.

Fix crash bug caused by plancache invalidation

https://github.com/ossc-db/pg_hint_plan/issues/41

After plancache is invalidated then revaliated, get_query_string
accesses query_list of invalid plansource then crash. Ignore invalid
plancache and get the correct hint string and Query node at the next
planning time during revalidation.

On the way fixing this, a bug related to planner reentrance is
fixed. That fix causes behavioral change for nested
planning. Previously outer-level hint (wrongly) overrides inner-level
query but currenlty outer-level hint no longer affects inner-level
query.

Fix compiling error on Solaris

The 'LDFLAGS+=-Wl,--build-id' option is for rpm building in Linux like
OS. The SunOS is not native support the option
'LDFLAGS+=-Wl,--build-id' . So, we disable this option in SunOS while
compiling.

Committed a bit tweaked version from the orignal.

Fix the previous commit.

The previous commit left a line to be removed. Remove it.

Do null-check of error_context_stack before use

The variable is accessed without null checking when planner is called
in the context of pl/pgsql. Fix it. Back-patched up to pg_hint_plan94.

Reporter: egashira-yusuke
Issue: https://github.com/ossc-db/pg_hint_plan/issues/42
Original-Author: sun-wei <30999182+Dagouhan@users.noreply.github.com>
Original-patch: https://github.com/ossc-db/pg_hint_plan/pull/45/commits/8fe092ef73a9af6cfb41e20717d7cb35aa74fce2

Fix regression tests.

Fix regression tests to work for PG12.

Follow the change in PG12.

Commit 428b260f87 breaks the prior assumptions by adding one more
planning cycle for updates on partitioned tables. Follow the change.

Update core.c based on PG12.0

The following commits changes the original functions in core.c as of
REL_12_0. Took in the changes.

7ad6498fd5a654de6e743814c36cf619a3b5ddb6
45f8eaa8e3031c9cb12deb1b5e294bc052b378f2
f49842d1ee31b976c681322f76025d7732e860f3
7ad6498fd5a654de6e743814c36cf619a3b5ddb6

Fix definition of is_dummy_rel based on changes in community

fix spelling mistakes in file pg_hint_plan.html

Use ParallelHint in ParallelHintCreate()

Silence some compilers

Some compilers seem to complain about the previous patch, that
prev_hint_str is used uninitialized. Actually it is not but move the
initialization code out of the PG_TRY() section so that such compilers
would be quiet.

Correctly handle planner nesting

pg_hint_plan assumed that plpgsql is the only source of nested planner
calls. Actually nested call can be made in any shapes. Most of the
cases doesn't harm but in a special case where pg_dbms_stats makes a
SPI call during query planning, that affects subsequent planner
work. Hints lose effect when pg_dbms_stats searches "locked
statistics" tables while planning the target query.

9.5 is not affected. Back patched back to 9.6.

Follow core's cobe/havor chages

Take in some changes took place in core code.

Commit 608b167f9f has largely changed the behavior around
CTE. Although I didn't confirmed that the all changes are valid as the
test for pg_hint_plan, just took in all plan differences.

Change version to 1.3.4.

Fixed a minor bug of 1.3.3.

Fix condition to regenerate gather paths

Core has additional condition to determine whether to generate gather
paths and pg_hint_plan forgot it. Fix it.