[sqlsmith] Crash in apply_projection_to_path

Hi,

the following query against the regression database crashes master as of
23b09e15.

select 1 from depth0 inner join depth1 on (depth0.c = depth1.c)
where depth0.c @@ depth1.c limit 1;

regards,
Andreas

Program terminated with signal SIGSEGV, Segmentation fault.
#0 create_projection_path (root=root(at)entry=0x6918e60,
rel=0x7f7f7f7f7f7f7f7f, subpath=0x69d6de8, target=target(at)entry=0x69d7428)
at pathnode.c:2160
2160 pathnode->path.parallel_safe = rel->consider_parallel &&
#0 create_projection_path (root=root(at)entry=0x6918e60, rel=0x7f7f7f7f7f7f7f7f, subpath=0x69d6de8, target=target(at)entry=0x69d7428) at pathnode.c:2160
#1 0x000000000067841e in apply_projection_to_path (root=0x6918e60, rel=0x69d5e18, path=0x69d6ee0, target=0x69d7428) at pathnode.c:2251
#2 0x000000000065ff20 in grouping_planner (root=0x22e1850, root(at)entry=0x6918e60, inheritance_update=56 '8', inheritance_update(at)entry=0 '\000', tuple_fraction=2615.2579411764709, tuple_fraction(at)entry=0) at planner.c:1737
#3 0x0000000000661f44 in subquery_planner (glob=glob(at)entry=0x6918dc8, parse=parse(at)entry=0x235e3b0, parent_root=parent_root(at)entry=0x0, hasRecursion=hasRecursion(at)entry=0 '\000', tuple_fraction=tuple_fraction(at)entry=0) at planner.c:758
#4 0x0000000000662e2b in standard_planner (parse=0x235e3b0, cursorOptions=256, boundParams=0x0) at planner.c:307
#5 0x00000000006f40ed in pg_plan_query (querytree=0x235e3b0, cursorOptions=256, boundParams=0x0) at postgres.c:798
#6 0x00000000006f41e4 in pg_plan_queries (querytrees=<optimized out>, cursorOptions=256, boundParams=0x0) at postgres.c:857
#7 0x00000000006f5c93 in exec_simple_query (query_string=<optimized out>) at postgres.c:1022