pgsql: Skip opfamily check in eclass_matches_any_index() when the index

Log Message:
-----------
Skip opfamily check in eclass_matches_any_index() when the index isn't a
btree.  We can't easily tell whether clauses generated from the equivalence
class could be used with such an index, so just assume that they might be.
This bit of over-optimization prevented use of non-btree indexes for nestloop
inner indexscans, in any case where the join uses an equality operator that
is also a btree operator --- which in particular is typically true for hash
indexes.  Noted while trying to test the current hash index patch.

Tags:
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REL8_3_STABLE

Modified Files:
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    pgsql/src/backend/optimizer/path:
        indxpath.c (r1.227 -> r1.227.2.1)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/optimizer/path/indxpath.c?r1=1.227&r2=1.227.2.1)