Break parser functions into smaller files, group together.

src/backend/access/common/tupdesc.c

src/backend/catalog/heap.c

src/backend/catalog/index.c

src/backend/catalog/pg_operator.c

src/backend/catalog/pg_proc.c

src/backend/catalog/pg_type.c

src/backend/commands/_deadcode/version.c

src/backend/commands/explain.c

src/backend/commands/recipe.c

src/backend/commands/remove.c

src/backend/commands/vacuum.c

src/backend/commands/view.c

src/backend/executor/execTuples.c

src/backend/executor/functions.c

src/backend/executor/nodeAgg.c

src/backend/executor/spi.c

src/backend/nodes/copyfuncs.c

src/backend/nodes/print.c

src/backend/optimizer/path/xfunc.c

src/backend/optimizer/plan/createplan.c