pgsql: Update extensions with GIN/GIST support for parallel query.

Update extensions with GIN/GIST support for parallel query.

Commit 749a787c5b25ae33b3d4da0ef12aa05214aa73c7 bumped the extension
version on all of these extensions already, and we haven't had a
release since then, so we can make further changes without bumping the
extension version again.  Take this opportunity to mark all of the
functions exported by these modules PARALLEL SAFE -- except for
pg_trgm's set_limit().  Mark that one PARALLEL RESTRICTED, because it
makes a persistent change to a GUC value.

Note that some of the markings added by this commit don't have any
effect; for example, gseg_picksplit() isn't likely to be mentioned
explicitly in a query and therefore it's parallel-safety marking will
never be consulted.  But this commit just marks everything for
consistency: if it were somehow used in a query, that would be fine as
far as parallel query is concerned, since it does not consult any
backend-private state, attempt to write data, etc.

Andreas Karlsson, with a few revisions by me.

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/2910fc8239fa501b662c5459d7ba16a4bc35e7e8

Modified Files
--------------
contrib/cube/cube--1.1--1.2.sql         |  41 ++++++++++
contrib/cube/cube--1.2.sql              |  80 +++++++++---------
contrib/hstore/hstore--1.3--1.4.sql     |  58 +++++++++++++
contrib/hstore/hstore--1.4.sql          | 114 +++++++++++++-------------
contrib/intarray/intarray--1.1--1.2.sql |  53 ++++++++++++
contrib/intarray/intarray--1.2.sql      | 104 ++++++++++++------------
contrib/ltree/ltree--1.0--1.1.sql       |  71 ++++++++++++++++
contrib/ltree/ltree--1.1.sql            | 140 ++++++++++++++++----------------
contrib/pg_trgm/pg_trgm--1.2--1.3.sql   |  26 ++++++
contrib/pg_trgm/pg_trgm--1.3.sql        |  50 ++++++------
contrib/seg/seg--1.0--1.1.sql           |  32 +++++++-
contrib/seg/seg--1.1.sql                |  58 ++++++-------
12 files changed, 553 insertions(+), 274 deletions(-)