Support USING INDEX TABLESPACE clause for PRIMARY KEY and UNIQUE

doc/src/sgml/ref/create_table.sgml

doc/src/sgml/ref/create_tablespace.sgml

src/backend/nodes/copyfuncs.c

src/backend/nodes/equalfuncs.c

src/backend/nodes/outfuncs.c

src/backend/parser/analyze.c

src/backend/parser/gram.y

src/backend/utils/adt/ruleutils.c

src/bin/pg_dump/pg_dump.c

src/bin/pg_dump/pg_dump.h

src/include/nodes/parsenodes.h