Fix for count(*), aggs with views and multiple tables and sum(3).

src/backend/executor/nodeAgg.c

src/backend/nodes/copyfuncs.c

src/backend/parser/gram.y

src/backend/parser/parse_agg.c

src/backend/parser/parse_func.c

src/backend/parser/parse_relation.c

src/backend/parser/parse_target.c

src/backend/rewrite/locks.c

src/backend/rewrite/rewriteHandler.c

src/backend/rewrite/rewriteManip.c

src/include/nodes/primnodes.h

src/include/parser/parse_agg.h

src/include/parser/parse_expr.h

src/include/parser/parse_func.h

src/include/parser/parse_relation.h