Fix optimizer and make faster.

src/backend/nodes/copyfuncs.c

src/backend/nodes/freefuncs.c

src/backend/nodes/outfuncs.c

src/backend/nodes/readfuncs.c

src/backend/optimizer/geqo/geqo_eval.c

src/backend/optimizer/geqo/geqo_paths.c

src/backend/optimizer/path/allpaths.c

src/backend/optimizer/path/joinrels.c

src/backend/optimizer/path/prune.c

src/backend/optimizer/util/indexnode.c

src/backend/optimizer/util/pathnode.c

src/backend/optimizer/util/relnode.c

src/include/nodes/relation.h

src/include/optimizer/geqo_paths.h

src/include/optimizer/paths.h