Add support to GIN for =(anyarray,anyarray) operation

src/backend/access/gin/ginarrayproc.c

src/include/catalog/catversion.h

src/include/catalog/pg_amop.h

src/test/regress/expected/create_index.out

src/test/regress/expected/opr_sanity.out

src/test/regress/sql/create_index.sql