We seemed to be doing that in this case.  This was caught by enabling
memory_protect_buffer_pool GUC.

Fix invalid reference to relcache entries.

After a relation is closed, the relcache entry
might be freed if its refcount goes to zero and we
should avoid further reference to it.

This is a fix to already existing bug and current
tests can cover the code changes here. So there is
no need to add new test case.

They were not kept up-to-date anymore anyway. Remove the actual tables.

There are still a few references to these tables in the management tools.
AFAICS they're in tests, and I was hesitent to remove them just yet, in
case we're going to use the existing tests as a guide when writing new
tests.

This bumps the copyright years to the appropriate years after not
having been updated for some time.  Also reformats existing code
headers to match the upstream style to ensure consistency.

They don't exist in the upstream. All but one of the callers actually just
needed list_member_*().

This fixes up whitespace and formatting issues in the code touched
by the last new commits. Separated into a single commit for easier
diff reading of the actual code changes.

Improves defensiveness of programming around pointer derefencing to
ensure that we don't risk a NULL pointer. Most of these are quite
straight-forward, those of note are discussed below.

In doDispatchDtxProtocolCommand() we relied on the result data being
created in zeroed out memory on CdbDispatchDtxProtocolCommand() which
isn't guaranteed for every compiler. Explcitly set numResults to zero
and also check the results for NULL.

Per multiple reports by Coverity

The IndexInfo structs are used by ORCA to decide which indexes match an
expression, and there may be some other similar use for them too. This patch
changes it to fetch the index expressions and predicates from the relcache,
rather than deparsing them directly from the pg_index catalog. The versions
stored in the relcache have been run through const-evaluation and
canonicalization passes, so they are slightly different. I believe the
versions stored in the relcache are what we actually want here, for the
reasons explained in RelationGetIndexPredicate() and
RelationGetIndexExpressions().

We always passed CurrentMemoryContext for them, so might as well remove
the parameter, making the code more readable, and always allocate the
return values in CurrentMemoryContext.

The real ones are in parse_expr.h and makefuncs.h.