Cleanup up include files.

src/backend/catalog/heap.c

src/backend/executor/execTuples.c

src/backend/parser/analyze.c

src/backend/parser/keywords.c

src/backend/parser/parse_agg.c

src/backend/parser/parse_clause.c

src/backend/parser/parse_expr.c

src/backend/parser/parse_func.c

src/backend/parser/parse_node.c

src/backend/parser/parse_oper.c

src/backend/parser/parse_relation.c

src/backend/parser/parse_target.c

src/backend/parser/parse_type.c

src/backend/parser/parser.c

src/backend/parser/scan.c

src/backend/parser/scansup.c

src/include/access/rtscan.h

src/include/access/rtstrat.h

src/include/commands/creatinh.h

src/include/commands/explain.h