Final optimizer cleanups.

src/backend/nodes/list.c

src/backend/optimizer/path/allpaths.c

src/backend/optimizer/path/hashutils.c

src/backend/optimizer/path/indxpath.c

src/backend/optimizer/path/joinpath.c

src/backend/optimizer/path/joinrels.c

src/backend/optimizer/path/pathkeys.c

src/backend/optimizer/plan/initsplan.c

src/backend/optimizer/util/joininfo.c

src/backend/optimizer/util/var.c

src/backend/parser/gram.c

src/backend/rewrite/rewriteHandler.c

src/include/nodes/pg_list.h

src/include/optimizer/paths.h

src/interfaces/libpq/fe-misc.c

src/man/postmaster.1