pgsql: Make GIN and GIST pass the index collation to all their support

Make GIN and GIST pass the index collation to all their support functions.

Experimentation with contrib/btree_gist shows that the majority of the GIST
support functions potentially need collation information. Safest policy
seems to be to pass it to all of them, instead of making assumptions about
which ones could possibly need it.

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/ae20bf1740c53494e15fadfd8c2c6444032a3441

Modified Files
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src/backend/access/gin/ginget.c | 6 ++--
src/backend/access/gin/ginscan.c | 17 +++++++------
src/backend/access/gin/ginutil.c | 21 +++++++++--------
src/backend/access/gist/gist.c | 17 +++++++++++++
src/backend/access/gist/gistsplit.c | 21 +++++++++-------
src/backend/access/gist/gistutil.c | 43 ++++++++++++++++++++--------------
src/include/access/gin_private.h | 4 +-
src/include/access/gist_private.h | 3 ++
8 files changed, 82 insertions(+), 50 deletions(-)