Clean up whitespace and indentation in parser and scanner files

contrib/cube/cubeparse.y

contrib/seg/segparse.y

src/backend/parser/gram.y

src/backend/replication/repl_gram.y

src/backend/replication/repl_scanner.l

src/backend/utils/misc/guc-file.l

src/interfaces/ecpg/preproc/ecpg.addons

src/interfaces/ecpg/preproc/ecpg.header

src/interfaces/ecpg/preproc/ecpg.trailer

src/interfaces/ecpg/preproc/pgc.l

src/pl/plpgsql/src/gram.y

src/test/isolation/specscanner.l